I would say that each group has a single Nuhn per hunting ground. I say this mainly because of the fact that the #1 way to become a nuhn is to defeat THE current nuhn. This tells me that each group has a single chosen Nuhn for that hunting ground. Now if the tribe is more mobile than what we see from the U tribe NPCs I suppose two or three groups could travel in close enough proximity to one another than females could move between the groups some what fluidly.
However, for the most part I would guess that tribes "set up shop" like the U tribe NPCs appear to have. This would mean that they stay put in the hunting ground and as they grow a potential nuhn will take up the task of spreading out and claiming a near by area (though that could mean something as far as 30-50 miles away) as a new breading ground and take nuhn status.
But it would be odd for any Tias to move between groups unless they think that the other groups nuhn is weaker(and they can win easier) than their groups nuhn. However, this could be seen as weak/cowardly since they are avoiding battle with their own nuhn. (such challenges may also not be accepted on the grounds that the Tia is not of their group, but this is just speculation.)
Onto the dispersion of 10-50 females per nuhn. Figure in what is likely 4-7 Tia in that group(based on birth rate) and you are talking about potentially 60ish people and any pets/livestock that need to be fed off a single hunting ground. I would imagine that food is at least a little scarce and feeding groups much larger than 100 people on of one hunting ground could be very difficult. (unless the tribe takes up farming, which just seems odd for most Miqo'te tribe for some reason) So this tells me that with the exception of a few groups that MAY have two nuhns who can get along well enough to share females in the breeding pool, most groups will probably start sending Tia out to find a new breeding ground when they get close to 50 females per nuhn.
I would then guess that the lucky Tia who secures such a hunting ground for the tribe would be granted a set of 10ish females to go set up the new "chapter" of the tribe. and with that the original group lessens their load of mouths to feed while the tribe gains more ground and strength.
However, for the most part I would guess that tribes "set up shop" like the U tribe NPCs appear to have. This would mean that they stay put in the hunting ground and as they grow a potential nuhn will take up the task of spreading out and claiming a near by area (though that could mean something as far as 30-50 miles away) as a new breading ground and take nuhn status.
But it would be odd for any Tias to move between groups unless they think that the other groups nuhn is weaker(and they can win easier) than their groups nuhn. However, this could be seen as weak/cowardly since they are avoiding battle with their own nuhn. (such challenges may also not be accepted on the grounds that the Tia is not of their group, but this is just speculation.)
Onto the dispersion of 10-50 females per nuhn. Figure in what is likely 4-7 Tia in that group(based on birth rate) and you are talking about potentially 60ish people and any pets/livestock that need to be fed off a single hunting ground. I would imagine that food is at least a little scarce and feeding groups much larger than 100 people on of one hunting ground could be very difficult. (unless the tribe takes up farming, which just seems odd for most Miqo'te tribe for some reason) So this tells me that with the exception of a few groups that MAY have two nuhns who can get along well enough to share females in the breeding pool, most groups will probably start sending Tia out to find a new breeding ground when they get close to 50 females per nuhn.
I would then guess that the lucky Tia who secures such a hunting ground for the tribe would be granted a set of 10ish females to go set up the new "chapter" of the tribe. and with that the original group lessens their load of mouths to feed while the tribe gains more ground and strength.