As mentioned before, don’t think things are that much “set in stone” and are mostly dynamic (i.e. core features largely depend on mob design)… Speaking of which: I’ll do a bit of “shameless” advertising 
Namely, just created a topic about that issue “Mob design” (broader concepts) and think that could “heal” most of the “do this do that” type of approach and realize that actually a lot of that depends on what the mobs/creatures are like (or behave like)
Therefore I hope some of you guys hop briefly and see what “came up with” as an idea/concept (and maybe even provide some feedback) on it 