When I was incharge of firearms instructing at my department, i employed the thought of using a knife for weapons retention. For the smaller and weaker physically, if someone grabs your weapon while in your holster, I have seen video after video of cops going around and around in this scenario. So I taught, carrying a fixed blade of automatic knife on the weakside, to be used to cut the wrist or stab in the gut an assialant trying to disarm you. My thought was no matter the size, if you cut the wrist properly, you disable the tendons and nerves and they will let go. If someone grabs your weapon, deadly force is authorized.
This came in handy one night when I got in a scrap with a 6-8' 300lb brick mason, who didn;t want to go to jail. I remember hearing the stiching on my gun holster ripping, when he was trying to pull my gun out. I simply pulled out my CKRT bear claw, and cut him from his pelvis to his belly button, and then took a chunk out his wrist. To my surprise, he let go. He passed out when he saw his own blood.
Always carry a knife, and think outside the box.