Mercenary Suggestion

I had a thought a few days ago. Mercenaries gain exp as well in group hits, why not let them level up also? With how little XP is gained per use, it would take a long time for them to grow even one level, but they are gaining experience, so why not reflect that? Further, this would be something game-wide. No one guild would be able to gain enough exp in one run to level up a mercenary, even the really low - level ones need more than what 1-10 pts of xp (typical xp for group kills) to level them up. Their stats would grow then based on fixed, predetermined numbers, so that there isn't any complaining about where the level up points get allocated to - Those have been predetermined, fixed, not something that would be dependent on the whim of the guild that actually leveled the Merc up.

*shrugs* may not be the best idea in the world, but it's not the worst.