I like how the MC actually teaches them and they actually learn, unlike some manga where MC just blitzes everything and the females are just there for eye candy.
Here the MC has been doing this for a long time, they haven't and it shows. No BS "oh well they are prodigies so they are immediately masters!" No, History has proven that in combat book smarts can only take you so far, if your not used to actual combat you will be more prone to panicking than some one who has already seen what happens when a bullet meets someone's skull.