I would be way more impressed if there was an AI that can play Overwatch. It's one of those games that are fundamentally hard for computers because of meta-gaming, map differences and ability combinations. It would be much harder for AI to converge on some single game-breaking trick, or just bruteforce possible strategies through blind trial and error and memorization.

Also, aim doesn't matter as much, so you wouldn't have to introduce some artificial restrictions. (Reaction time does give you a big advantage, though. You can counter a lot of things simply by reacting to voicelines in time.)