Ah yeah, the three headed beast and the overarching evil was more of a setup for future development on the game, so there is something to get into rather than just a hard ending. We could probably make that a bit more obvious in some ways, so it's clear there isn't much else to do with that at the moment.
Haha sorry you spend so long searching the grasslands! It is the curse of these open-world text games. It was meant to be somewhat reminisint of the old school adventure games, like kings quest. But with that comes the frustrating bits as well, like trying to figure out if you've gone everywhere you need to go.
There is no more to the armadillo or the dog, unfortunately. Not yet anyway, those are just little extra things we sprinkle in to fill up the space.
In the third level of the plain of pleasure, there is a set sequence of things you must do with the males, in order to keep them in line and not let it devolve into a mad orgy. If you figure that out, you should have the option to claim the chieftain.