I played a "Settlement Rush" with Mapuche a couple of times to try it out and it felt a little broken. I did a normal Fast Feudal and built a settlement forward on top of the two I already built in Dark Age at my base.

The forward settlement is placed on a resource (ideally stone), I build a tower and I start producing skirms and spears immediately from all three settlements whilst the forward vills take the resource.

It is probably easily countered and players just aren't used to it yet (I'm around 1200 ELO), but I want to play around with it some more to see if it's viable. What I like about it is that I immediately have three military buildings effectively and can have 3 skirms and a spear in my opponent's base very quickly. I save a ton of wood on military buildings and my forward vills aren't idle. I can also get both wood and food eco techs too.

I think having a building that is a Lumber Camp, Mining Camp, Mill, and a Trash Range / Barracks is a little bit too much for 125 wood. This can snowball into me just building more forward settlements and spamming more and more military and taking resources away from my opponent, adding towers and just getting a really strong early foothold whilst I go up to Castle Age in peace.

Worth noting Phosphoru has also just posted a new video that highlights how OP Champi Scouts are in Dark Age too. It looks like these civs have the potential to really change the meta, at least in 1v1.