Pretty simple one, really.
With the way the power curve on Arelith has gone, several of the classes have fallen behind, including Barbarian.
SUGGESTION: give standard PURE CLASS Barbarian the tribal warriors, on top of rage bonuses.
Given how comparatively weak the tribal barbs are, I cannot see how it would “break” anything, but it would definitely help the barbarian to do his thing. It would also give barbarians a way to deal with opponents with DR, as a pure barb has tribals with +5 weapons. And, at the same time, said tribals are quite limited in terms of their AB, AC, and DPS