If I was making a game this way, I’d probably have an initiative system in reverse. There would be an advantage in declaring your intentions last as you know what everyone is doing. Maybe each attack has a speed factor that determines the order blows land. There’s lots of ways of doing it, but the crucial thing would be not knowing the outcome of the each character’s action before deciding what to do.
Are there no games like this? Shit, maybe I’m onto something here.
Josh Sawyer's table top Pillars of Eternity used that at some point (I don't know if it still does, it's changes as is gets developed) - characters roll initiative and commit to moves in reverse order. I actually like the idea a lot. The downside is that we would need to get rid of rolls - fine for computer game, less so for PnP. Having to double guess what players will do plus making plans based on uncertain outcome is absurd way for things to spiral into chaos. I do like how this system trabskates "reaction time" though.