In my experience "sneaky AI" makes AI MUCH less effective, melee or not.
AI has a couple of advantages: taking a lot of shots, and finding quircky, impossible angles of shooting to ruin your day.
Sneaky AI ruins volume of fire first and foremost, leaving the player the initiative of methodically flushing out cover. Players have huge advantage in this area, especially with aggressive tactics. Met with agression, sneaky AI will fold and try and hide, instead of unloading a double sawedoff in your overextended ass.