So, I'm picking Global up again.

What kind of stat build does the Hermit have? What's the Crusader's DEX, and can it hit normal training monsters with it's adequate equipment?
What are the skillbuilds of each character?

Specifics like these could give me a better idea on which one would be easier for you to pick up on and train faster.

116 DEX on the Hermit. High DEX Sader, he's at 101 (116 with equips). Last I remember ghost pirates were the training spot for him, and I'm pretty sure he could 100% hit them.

Plus your preferences. Bosses? You like having lots of mesoes? Speed?

Never been much of a bosser, not without lack of trying, but I was never one to get the most damage on single bosses, never actually got to attempting Zak or anything (seriously, at least). I do, but if I have a lot of mesos I usually spend it, so I usually just go with the amount I need for training, and store the rest on another character incase I ever need it. If by speed you mean moving around, no, if by training speed yeah, I'd prefer faster.