Yes it's a tad more complex...than the US Army being credited for driving them onto reservations. The Army was able to do so due to the lack of hunting. The Plains Indians subsisted on Buffalo and the Buffalo on the Staked Plains were literally there in 1874 and not there by 1878. Not there as in having vanished from the face of the earth.
If you haven't read it, read Getting a Stand. The Time of the Buffalo is also good reading.
Look, the Comanche adapted. Of that there can be no question. The problem is, for the old ways of raiding to continue, the Comanch had to be nomadic. To be nomadic, the Buffalo had to exist. They were wiped out in the Comancheria in about six years. Thus, the raiding way of life vanished in the six years that the Buffalo were wiped from the area.
The Comanche also were just the dominant tribe, not the only one. The other three were there too.
