The difference between an attack that is hard to defend and an attack that will hurt if it succeeds is very slim.
A robot has more strength and reaction to stop / reroute a successful attack
In the world of non-weapons (which I'm more familiar with), say a kick needs to go into the space my body was occupying a moment ago, or avoiding it is not realistic.
The difference between an attack that is hard to defend and an attack that will hurt if it succeeds is very slim.