You know they are adding AI to drones fighting in Ukraine (on both sides). Mostly to deal with signalling scamming that prevents remote operators from controlling the drone.
Whether you consider your opponent in a war sub-human or not is completely irrelevant to all the engineering problems you have to solve here.
Reliability is absolutely important, because you want that opposing tank or helicopter or soldier etc to no longer be opposing you. (But, of course, reliability is only one aspect, and engineers make lots and lots of trade-offs.)
What context do you have in mind where you need a robot to shoot people?
