Asa just look like that mass recruiting tribe that's at the start of every world and eventually drops out the top 5 or disbands due to poor leadership.
I like the look of BAD lots of players in there I recognise and they have a good spread through out the SE, maybe need to drag some more players into the world around their rim to secure it.
RWS also look a good tribe, recognise some names their and they got a few world winners sitting in their ranks too. They seem to be dead center of the world which with out smart diplomacy will ruin them (having borders with other top ranking tribes like BAD and Asa). I can see them doing well if they have good diplomacy and pick their enemies and allies wisely.
Nan I've fought against some of these players on the rim of EN18, their leadership is good and there are some good players in their ranks but on that world their recruitment policy wasn't the best. If their recruitment is the same here they will be giving home to inexperienced players and maybe some sandbox players too.
Yak are also a tribe from EN18, they looked good their and I see it's the same leadership here so I can see them doing well and securing the NE of the world with out too much competition.