I need 3 manticores, but having crawled over the mountain trying to find encounters that have any, I've only found one. I know that there were a few mixed troops which included a manticore on the way up, but they might all have been permanent defeats, rather than respawning.
Is it even possible to do this, or is it yet another quest where if you don't do everything exactly right (in this case, avoid encounters) you automatically fail?