I think it's very interesting to collect ideas for new tribes. If more people would share more ideas, this could be good ;-) Hereby I would like to initiate that...
For example, I listed some random ideas in some randomly chosen categories:
a tribe which is strongest in the midgame in comparison to early game and late game where it is weaker - whatever midgame is precisely.
a simple tribe which could be attractive for beginners and for people who don't like too much complexity
or a tribe with 3 different trainingssites
Wells which are different to other wells
Deep mines which are more efficient than non-deep mines
Diamond mines: Produces Granite, and diamonds, which will be more important for the tribe than diamonds for atlanteans, but less important than marble for the empire
Also possible: Quartz mines (similar)
Workers and tools:
a tribe where experience of workers can be very helpful and plays a more important role
workers which fulfill different purposes
Cheap tools, like 1iron+3logs=2tools, or any other wares could be used for tools.
or no big need for tools at all
tribe where soldiers do also something else than fighting, for example building or other work Hammers not only as tools, but also as standard weapons
no meat, no fish. (vegetarian tribe)
or: A tribe with game keepers which are not so efficient, but also with "game breeders" which turn one animal into two animals, which would be more efficient. so one would have to put game keepers, game breeders and hunters into the correct relation
Tribe without iron and gold: smithies are smelting works at the same time / consume the ores
Many shields for defense. Maybe a tribe which is even more defensive-powerful than atlanteans? Or soldiers who never evade
cheap transport animals
transport animals which can be transformed into meat