Allah has never left the earth, the habitation of earth and humanity without a leader. Everywhere, where their was a survival of human beings (a human society) of any kind, a Leader has come into place. A leader by every aspects needed according to the time. Here, comes the hierarchy of prophethood. How prophets are ranked? According to how big the responsibility is on their shoulders, size of community they have to deal with and other complex parameters. Other than prophets, even men are granted leadership. For example, Hazrat Zulqarnain. Even great men have played the role of a guide, for example, Ashab e Kahf. The most convenient example can be the leaders of our time and recent periods. Basically, we always have a leader who leads us to justice. This system where people are not left without a leader is called Nizaam e Wilayat (System of Leadership). Wali means leader. Here, I'm talking about Waliullah (Leader appointed by Allah).
Now, what is this hierarchy? First of all,  our absolute leader is Allah — 'Qul hu wallahu Ahad'. Only he. But in order to reveal his leadership, guidance, kindness, help etc. we need a system. This is why we need Nizaam e Wilaayat. Allah appoints prophets and Imams as our divine guides. These are those entities which bring the command of Allah (سُبْحَانَهُ وَ تَعَالَى) in the society. And because they are immune from error, they are irrefutable. Because they are irrefutable, they must be followed undisputedly. When they are followed undisputedly, it brings harmony and order in the social system like the system of military and defence. How disciplined they are! Because they have to follow the commandments in which there is no question and hence, no chaos. So, Allah (سُبْحَانَهُ وَ تَعَالَى) and then his divine guides chosen from among people should be followed in a similar manner. After that there are other people too who are given this responsibility as an obligation or they achieve it through their hard work. Such leaders are refutable most of the times. Their work is only to pass the divine law, values and conjuctions of Allah (سُبْحَانَهُ وَ تَعَالَى) in the right way. They don't have to say anything from their own side. They are coordinators or minor leaders. For example, the scholars, the imam e Juma, Imams of mosques, parents. Their role is to spread the message. Pass it to impose the divine will. 
All the leaders should be obeyed. In order to obey Allah (سُبْحَانَهُ وَ تَعَالَى) we need to obey his Wali irrespective of there ranks. But as per the nature of hierarchy, one supercedes the other. The ones refutable should connect their orders to the irrefutable ones (Ambiya/Aimmah). If they don't do so, respect them but don't obey them because here their order can be replaced by the order of ones above them. So, moving in a bottom to top order of leadership — Parents hold the first right to leadership, then Imam of the mosque, then Imam e Juma, then an appointee of your region — for example if someone holds the authority of wilaayat for a country or state. Then, the appointees closest to the wali e Asr or irrefutable Wali of your time. Then, the prophet (صلى الله عليه وآله وسلم). Then, Allah. 
Thus, this is the system of wilayat from the perspective of history and also from the perspective of region.

Now, question comes up about woman? Question is genuine and begs an answer. Woman don't hold the position of leadership. They hold the role or responsibility but not the position on a larger level. Here, I'm talking about physical leadership. As an opinion, the female gender naturally seems to be a superior gender. It holds a lot of other major gigantic roles which can never be taken by men. Now, in a team, if the person who is extremely valuable and has a lots of roles to carry. Does it ever happens that such a person should also be burdened by this role of leadership? No. Secondly, men are by nature more stronger physically and because of their role in the society only, they are also more discrete and straight forward in thinking. Women are greatly attached to many things very closely. 'Lam yalid wa lamyulad' — Allah the absolute leader who is free from all attachments, would also like to give wilaayat to someone who is less prone to bending towards attachments. Now, I'm not saying that woman cannot hold this position. They certainly play this role but they are not given this position because of the other burdens on them. 
Women are leaders and this is undisputable. They are leaders ideologically, in a symbolic way and in the matters purely related to them. Like Mawla Ali (عليه السلام) is a man in portrayal. He will not teach or explain the roles solely related to woman. So, a woman needs a symbolic leader whose footsteps she can follow. A leader of heart who she can see as an example. A woman cannot step her foot in Imam Ali's (عليه السلام) shoe. She needs a woman for that. Who will tell her how to treat people? Who will make her aware about her own identity? Answer is : The ones who are the leaders of woman and the ones who have taken their legacy ahead. The one who can be called Sayyadatun Nisa il Alamin. It is Fatima tul Kubra, Khadija tul Gharra, Maryam e Muqaddas and all those who have carried their legacy ahead. These are the symbolic and ideological leaders of a woman. Take the concept of leader I said before and combine it with these leaders. Bibi Fatima (SA) is the leader of woman. A Woman should follow her until she becomes like her. Women have to say what she ordered them to say. Stand where she says 'Stand!'. Sit where she says 'sit!'. Her order is irrefutable. In order to become a perfect woman, a woman has to follow her. She should be an example and role model for woman. Now, how to follow her? Study about her. Find her traces in history. Try to understand why a woman who just lived so less (18 or 28) has become eternal in history. Don't we want such eternity. But for that women should struggle. They should struggle to get closer to her character. She is Imam of every woman. Though, only women are not bound to follow her but rather every human being but she is more important and specific for a woman. We should not only love her, but drive ourselves on her path. It is so bad that woman don't take her as there leader. They don't do hijab but lament for Hazrat Zainab. All this love is useless. 
In conclusion, It is crucial to study about Bibi Fatima (عليه السلام), Bibi Zainab (عليه السلام) and women in history similar to them. If  women don't follow them, they have not attended completely to the message of Ghadeer. Traditional woman was submissive to oppression. Today's woman is herself an oppressor, heedless, worthless; who adores the fake beauty but can't perceive the character. Has no sense of self-sacrifice. A follower of Bibi Fatima is not actually like that. She has the ability to conquer the world but sacrifices herself to the duties given by Allah (سُبْحَانَهُ وَ تَعَالَى). She like Bibi Fatima (عليه السلام) uses her outer beauty, exploits it as a useful tool, sacrifices it with the sword of time and space, and burns it in the afflictions of this world. Why? To defend her inside. To bring her inner character. To shine her inner beauty. She kills her outside body in honor of the inside character and as a gift or sadaqah to create an ideal Islamic society. Such a woman is the Shia of Fatima (عليه السلام), Maryam, Hajra and all the noble names. Ghadeer for a woman (and muslims in general) is not only the acceptance of Mawla Ali (عليه السلام) as there Leader but also the acceptance and recognition of Hazrat Fatima (عليه السلام), the pure. 
Ghadeer is the only place which not only connects Imamate with nabuwwat but also resembles Islam as a political religion. Shame on us that we have accepted tyrants as leaders. We respect this worthless system of tyranny and are heedless about Nizaam e Wilaayat. If we really understand the message of ghadeer, we can never accept 'Taghut' to rule upon us. But we accept oppression. We are corrupt, top to bottom. The one who says that religion is separate from politics is neither aware of Religion, nor politics. Politics is bad because good people don't pay attention to it. Islam covers every dimension of life. But we don't follow Islam. We follow mawla Ali (عليه السلام) like Hindus follow Ram or Christians follow Jesus. We don't accept them as our leaders but rather as some holy figures who had a legacy. What is the use of wasting time on such personalities when we don't have to do anything with their character and leadership? Our leaders are our leaders in all aspects of life. And yes only these pure ones. You know the impact of ghadeer in politics? The banner of palestine is kept strongly by Shias only. Palestinians are Sunnis and so they asked help from their pretend leaders only. But they were duped, betrayed. They felt leaderless and forgotten many times. Because they didn't had a wise leader. Sometimes they even were deviated from there path. Muslims establish empires that caused bloodshed, were unjust and based on the old baseless system of monarchy like Ottomans, the Seljuks, Ghaznavis, Mughals etc. We as muslims feel insulted that these empires were muslim empires. If muslims had remembered Ghadir and accepted Nizaam e Wilaayat. All the administrations would have been called 'Islamic' Empires, not 'Muslim' Empires. People, irrespective of there faith, would have loved to take pride in such empires and rulers of Nizam e Wilaayat.  Today, Iran is Iran because of Nizam e Wilaayat. In Lebanon, there is a Shia organisation, even some jews have supported it. A jewish scholar said, "They show courage, they show disciple." Where does this disciple come from. It comes from Nizam e Wilaayat (Leadership).
Mawla Ali (عليه السلام) loved Bibi Fatima (عليه السلام). Respected daughters a lot. Our leaders were those who gave women opportunity, wings, a freedom to speak, to express but yes were strict in order to direct them in the right direction and in order to point them out. Just like a person having love for someone does. What we have done to this? In what way have we followed are leaders? Does leadership means celebrating a day for them,  reciting poetries, eating delicious food? Do good to people this day. And say if someone asks, "My Leader Imam Ali, Imam Hussain. My leader Wali e Asr has taught me this. I am helping you as a tribute to my leader." Our leaders dealt with woman in a compassionate way. They loved them. Mawla Ali (عليه السلام) grieved and was in pain for what bibi Fatima (عليه السلام) had to endure. It is a matter of shame that we have never realised the honor of woman in such a manner. Even when they strictly commanded them or got angry, such treatment was in love because they wanted to direct them in a right direction.