is any one of them over powered?
Boone is. Even with 3 charisma, he is one shot killing every remotely weak enemy in the game. Strong enemies don't stand much of a chance against him either.
I'm on very hard, hardcoe, and the game is way too easy with Boone. It didn't help I made a sniper character. Between the two of us, if we get the drop on a mob, we can wipe them out before they get anywhere near us. Even when he stupidly whips out a melee weapon I'm making him carry because he's also my pack mule, he still crushes our enemies.
Before people tell me that I'm complaining about the game being too easy when all I have to do is get rid of Boone, my response is simple. At level 10, he's still the only companion I've managed to find. I don't want to read spoilers on my first playthrough, so I haven't cheated to find out where the others are. And I need a pack mule with 2 Str and hardcoe mode on. Plus, even when I find a new companion I might keep him. The roleplaying opportunity is too good to pass up. I found a spotter with even more hatred for the Legion than I have.