It would probably have to be quite impressive AI to resemble a living, breathing player Just turn EC into a MMOTuringTest
well tyranids do not behave like players I hope but in general, it's very hard to make an npc behave like a player - not sure if any game will ever achieve that perfectly. getting close to it is a magnitude easier.
You maybe can look to STALKER A-life with the Smart Terrains. It's still one of the best AI jobs system...