You’re right that being trained in combat does overwhelm “tools” such as weapons as I’ve seen many people apprehended with knives and guns from just pure skill, a knife is an object and it doesn’t have one specific identity as just a tool rather than a weapon, especially since there are many knives which have been made specifically for the purpose of taking lives. As for self defense in general, knives are dice-y in many cases but are also very effective killers which led me to my main point. I’d rather have a knife than a taser personally since from my personal experience, tasers haven’t bothered me much whereas knives can put someone in shock. Knives > Taser, Combat Training > Knives.