With the groupies, there's a small chance of getting a variety of desirable traits, and the eyeballs are completely random. But I've yet to get a groupie with anything but an NCL mane. I don't see any reason why more manes can't be added to the pool as well.

Scarce, Normal and Thick would remain the most common by far but there could be a chance that the lion could have any mane excepting Royal, Incubus or the August manes (or possibly just use manes from the custom list full stop). There could even be a groupie exclusive mane shape only found on the teen males.