Well, I'll admit that I'm being a little disingenuous by writing him off as a complete harem protagonist because romance isn't really a thing in the Crossbell games. It's just that the harem aspects of him are the worst part about his character. Everything else is fine.
Anyway, back to Zero, I think the game was very good about all that stuff. If you had to compare someone to Olivier in the Crossbell games, it'd be Randy but he doesn't take the creepiness factor to the level Olivier does. Not to say I hate Olivier or anything, since I still love the guy, but Randy's definitely the playboy character done right. Or done wrong since he never scores? Heh.
Ao, on the other hand, is definitely a mixed bag for me. Randy still stays legit though, so thank god for that.