I've seen Doug Marcaida before, he does some karambit clips. He did say some very good and relevant things, and when he demonstrates with a karambit or knife he is very flowing.He made the point that if he was going to attack with a knife he would get in close first , which is the way to think.However, reality is a lot different to what we imagine and what our theories are.
If you are carrying a gun and you feel threatened or at risk, then it should be in your hand already, if you do not feel threatened and have to pull your gun to deal with a threat, then you are missing something and you need to re evaluate what you believe and incorporate it into your training.
I find that looking at old historical martial arts helps me to understand weapons better, you can see how people back in the day behaved, and not against imaginery opponentshttps://www.youtube.com/watch?v=AQDr13T ... GCwcjhrOdA
Thick clothing can stop swords!! so I imagine that knives would be even easier.