Is it assumed that all the kill bots are networked? It makes sense to have then connected but how would that be possible? In reality only so much data can be transfered at once and assuming that they are networked through a hivemind, most likely based in orbit to broadcast to as much of the planet as possible, it would only be able to balance so much. Similar to the way you have bandwidth for an internet connection. The Hive mind could only control so much at one time before reaction begin slowing too much to be effective, not just while hunting humans but even simple things like manufacturing kill bots. assuming that is so humans spreading out and trying to distract many parts of the hive would slow everything down, of course this requires ridiculous man power. If they weren't networked, well that a different problem, more autonomy, most likely more heavily armored and weaponized. If they weren't networked they would work better as either lone wolves or in small squads, harder for humans to find and they would have to be heavily supplied so as to need fewer returns for supplies. The only upside to these would be that the reaction to their destruction might be slower but not by much.
Either way in is not an easy thing to over come but possible, given time and hoping that the robots consider management of their resources slightly higher than destruction of humans.