I'm not sure what that's supposed to mean, because improved trip seems like a decent way to simulate skill at foot sweeps and throws.
Come and get it, on the other hand, isn't narrativist at all, because it isn't driven by story concerns: plot, character, etc.
More than anything, come and get it seems Euro-gamist. It's a neat little game mechanic with a patina of theme that comes right off if you scratch at it looking for simulation.
Well, here's an interesting question. Lets say I try and foot sweep you and miss. So you get to try and foot sweep me? Why? I've seen MMA matches, if someone tries to knock someone else off their feet and fails, the other person doesn't necessarily have an opening to knock the first off their feet (it was in for clear balance reasons).
Improved Trip was in for fixing the balance fix in the first place (lol) and letting you actually make trip attempts. Which you could make against anything. Why can I trip an Ooze? What does that simulate? I swing my feet through a lump of jelly, and it falls over on its back?
I guess you can modify it so trip attempts only work on things with humanoid features. And introduce a new rules system to cover non-humanoid creatures.
This is the problem. I am promised simulationism will work without introducing a rules manual that can be used to kill home intruders, but examples of 'good simulationism' include GURPS, which DOES have a rules manual that can be used to kill home intruders (once you add in all the submodules you need to make the game simulationist) and the editions of D&D that I'm promised are simulationist (uh... 3E) have rules that don't seem to be either good simulationism or GOOD RULES. PERIOD.
Forgive me for a feeling of creeping skepticism here.
(also, seriously, find another whipping boy than Come and Get It, which suffers from the exact same problem as Trip mechanics - it assumes a certain class of targets, and then works on absolutely everything)