one of my friends found follower with and used P90

.
But yeah I got one right now, the thing is, once you get tent or hotel or base, you must tell him in dialogue to meet you some place before he dies (afaik i only lost in encounter he never died before).
And yes, most of them all use throwing knives. But mine is fucking kickass with his so I dont see the problem

(afterall, they can obviously use melee too, and they level up, and aren't ever perm-dead if you do it correctly. So level him up some and he can use BG or SG in no time

)