why did they have warrior tribes?
warrior tribes where introduced into the tribe as protection against other tribes. they where pretty much the army of their day and where there to fight off threats. some of the reasons to have a warrior tribe was due to the lacking of reasorces and crops so the different tribes had to fight for what they wanted and it wasn't pretty. they would also fight of land space and to restore manner which was the spiritual power they believed that mana could only be brought back through ancestors or through warfare.
being a warrior was nothing fun, its a war and you can die within battle. it takes a lot of guts to do something like that. the Maoris would sometimes eat the remains of the other tribes victims as a representation to not be messed with. cannibalism was used to fuel the diser of gaining manner and the Maoris where so good at it that they shear never defeated.