Well, it would have to beat a human's micro first.

Remember, it's not just doing predictable actions every time. A lot of it is dancing back and forth and trying to bait your opponent.

So an AI might say "focus firing a stalker is the most efficient" and the human player blinks it away. Then it chooses the next target and the human player blinks that away as well. And so forth until the human player runs out of healthy stalkers and simply walks away with hurt stalkers having done enough damage.

The "correct" solution might have been actually to run past your opponent's army and to surround it spreading the damage. Even when you blink out you're still close to the enemy army because of blink's range.

There could be a mathematical model that predicts whether to run past or to attack or to stutter-step, but humans do this based on experience. AIs are not close to this level of sophistication.