Mobius' work is centered on having the closest retail experience possible, not on arbitrarily balancing classes. There is a config file for you to do so on your own.
As far as I know, there are only 2 things that Mobius has willingly customized here, and neither of them are related to classes.
- On Mobius, max. enchants are hard-capped at 16, where on official servers they are hard-capped at 50 (both retail and classic), although soft-capped way earlier due to low enchant chances.
- On Mobius, bonus experience granted by runes doesn't work on Raid Bosses, on official it does.
Now, it can be completely possible that something might be missing on classes, like a passive skill with the wrong effect, or a chance skill missing, and it's the work of the community to keep adding and fixing everything so it's the closest experience possible to retail.