My fiance is fixated on friends?

Being a 'social climber' or freind whore is not a problem in itself. it's if he was talking to those girls and trying to keep it secret from you, you should be worried, but honestly it just sounds like he has a gregarious personality that maybe you find a little intimidating because you're more introverted. it's good to have a couple where one's the shy one and the other is more outgoing, i think it's healthy balance.