I think of Jericho and Clover as the difference between pure evil and just plain crazy. Jericho is just a sociopath like all Raiders and he has no respect for human life and spent his youth sadistically torturing and killing wastelanders for their valueables. He claims to be "reformed" only because he's too old to hang out with Raider gangs, but he has yet to actually leave his bad habbits behind such as when he almost [censored] Jenny Stahl.
I would take anything you found on Moriarty's computer with several grains of salt.
The difference between these two followers is that in one case, you've got a submissive, traumatized slave to do your bidding. This slave whines a lot and her lines show some sort of personality disorder - eager to start a fight, then crying for help instantly, then immediately eager to initiate another fight, and then immediately bored. In the other case, you've got someone who's lines show that he's happy to be out on the road and who definitely does not do anything particularly evil unless you start to go on a rampage, yourself. His lines and behavior are consistent and show that he's got a solid, mature personality, which isn't particularly evil at all.
The first option may be pleasing for some male phantasy scenarios or something, but I'd hate to have someone like that around in my game.