i like the idea about dretches not clipping the tyrants and goons, but the problem is that a dretch could leap through a tyrants chest cavity aline-style (which despite being hilarious would still be kind of weird).
i was playing a game once, and a goon got stuck down the tunnels in tremor, and he couldn't get out. i was a dretch and so acted like a portable ledge, the goon leaped as high as he could and i wallclimbed to beneath him and he jumped off me out of the tunnels.
my idea is this, to make dretches easy to push around, like if a tyrant walks (not charges) into a dretch its simply pushed out of the way, this makes much more sense game-wise as there is no way that a puny little dretch can stop a 300 kilo tyrant.
perhaps even change it so that you can push ppl out of the way without shooting them (for humans)