
On the note of female Seekers leaving their current tribe with a Tia to start a new one- I actually imagine it happens fairly often. Even with the population ratio of male to female Miqo'te, there are still going to be a number of Tias in a tribe, not all of whom are qualified or willing to challenge the Nunh. In fact, if too many of them are present at one time, it would cause problems- they don't serve as active hunters for the tribe, and spend a lot of time squabbling over politics and trying to rally the tribeswomen to their side. Any more than two or three Tias under a Nunh in a tribe the size of the U would be unsustainable. So with that in mind, and given the precedent of many social animals that live in similar family groups (lions being the obvious most apt comparison) as well as human societies with comparable social structures, it should actually be far more common for a Tia to leave his tribe to start his own or latch on to a floundering tribe than it is for one to stick around and challenge his birth tribe's Nunh, or at least equally as common.
And I don't think every female Seeker would balk at the offer to start a new tribe and leave her current one. We've seen that the allegiances of the U tribe huntresses are fluid, and though it's an upheaval from their established life, many people do feel fine moving to a new region or a new job, so to speak. Unless the situation was catastrophically abusive, or there were personal motives/fears in the way, most Seeker women wouldn't be entirely averse to leaving their current tribe and its Nunh. But it ultimately comes down to personal choice in that area. The Nunh might be a close friend, a father, or someone seen as more than just the guy everyone uses to sire children. Or he might have threatened those who seek to leave his tribe. The given Seeker might be unadventurous, and happy to stay close to the land where she was born, or scared of the outside world. Or she might really hate the Tia who's trying to leave the tribe. There are an equal number of reasons to leave as there are to stay, but it's pretty apparent that Seeker tribe allegiances are fairly fluid within what the canon presents us.
As for the distribution of power, it is absolutely established as in favor of the men of the tribe from what we've seen in-game. There's a grey area, thanks to word of god from the devs, but the U tribe absolutely fits the bill of a patriarchal society, albeit one that is not actively destructive to the lives of those within it. You should definitely feel willing to use that grey area to your advantage for headcanon, fanon, and backstory, since there are definitely ways to interpret the system with Nunhs and Tias into something that is ultimately controlled by the women of a Seeker tribe, but from the baseline established by the basic structure of Seeker society and from what we've actually seen in-game, it's way easier to interpret Seeker tribes as societies where men hold true political power.
And I don't think every female Seeker would balk at the offer to start a new tribe and leave her current one. We've seen that the allegiances of the U tribe huntresses are fluid, and though it's an upheaval from their established life, many people do feel fine moving to a new region or a new job, so to speak. Unless the situation was catastrophically abusive, or there were personal motives/fears in the way, most Seeker women wouldn't be entirely averse to leaving their current tribe and its Nunh. But it ultimately comes down to personal choice in that area. The Nunh might be a close friend, a father, or someone seen as more than just the guy everyone uses to sire children. Or he might have threatened those who seek to leave his tribe. The given Seeker might be unadventurous, and happy to stay close to the land where she was born, or scared of the outside world. Or she might really hate the Tia who's trying to leave the tribe. There are an equal number of reasons to leave as there are to stay, but it's pretty apparent that Seeker tribe allegiances are fairly fluid within what the canon presents us.
As for the distribution of power, it is absolutely established as in favor of the men of the tribe from what we've seen in-game. There's a grey area, thanks to word of god from the devs, but the U tribe absolutely fits the bill of a patriarchal society, albeit one that is not actively destructive to the lives of those within it. You should definitely feel willing to use that grey area to your advantage for headcanon, fanon, and backstory, since there are definitely ways to interpret the system with Nunhs and Tias into something that is ultimately controlled by the women of a Seeker tribe, but from the baseline established by the basic structure of Seeker society and from what we've actually seen in-game, it's way easier to interpret Seeker tribes as societies where men hold true political power.