The problem is that every step I can think of to use against AI drones is also a more potent weapon when they control it too.

Like okay, it is easy to set up a high power diode laser that can target any image sensors. The laser can move fast and target objects far faster than any weapons system and do so cheaply. However reversing this, that same system can target all human eyes exactly the same way, permanently blinding thousands of people in under a minute.