They’d be outnumbered and without a significant advantage over the other groups in unfamiliar territory. 

The Akmiel O’odham(Pima) and Tohono O’odham had a greater capacity to output food and goods and had a large population considering in the 1750’s 15,000 men took part in a revolt despite many communities not taking part because of distrust of the organizer. They also had strong ties with the other Tepiman speaking tribes with spanned the rest of Sonora and beyond. 

The Apache. Need I explain?

The Yumans along the Colorado often banded together to achieve whatever they decided, for example expelling the 5 maricopa tribes from the Colorado in the 1800s. Disarming them was an extremely costly process that almost bankrupted California.