Because the German tribes were too strong and numerous for Rome to effectively take on even in standalone battles.

Maori is a collective term for all the natives of New Zealand of which there are numerous tribes and all are represented in their areas by Runanga (family representatives of sub-tribes within the greater tribe) or Iwi Liaison Officers (tribal representatives voted into their position by descendants of the tribe).

Oglethorpe encountered numerous native tribes during the colonization of Georgia. The most prominent of them was Tomochichi and his tribe of Yamacraw, but there were other, larger tribes in the area, such as the Lower Creeks.

One of the national tribes that live in Arizona rainforest is the Ticuna tribe. They are also called Maguta, Tucuna, Tikuna, or Tukuna tribe. They are the most numerous in the Arizona rainforest.

The problems facing Nigeria is too numerous to mention .Nigeria is a diverse nation in term of Religious and tribes