[@shamrocknroll]

Admittedly, some classes serve character description more than they do an incredibly different combat orientation. I'm always open to suggestions/critiques so I don't mind your questions at all! If there is some redundancy in classes, I can chip away at the fat. 

You're actually not entirely wrong regarding pact magic, but this is somewhat by design. Lore-wise pact mages are considered inferior in most mage circles because typically pact mages weren't born with any potential for magic (magic potency exists on a spectrum). It's in many ways an arbitrary distinction that comes about because of social stigma. Pact mages can learn other spells, but their potential in mastering said spells are limited whereas there are some specific abilities granted to a pact mage (depending on their patron). Mages seeking to gain particular power in one field of magic typically undergo a rite of passage that binds their magic to a particular school. Pact Mages are the exception to this as their magic doesn't come from them. It isn't theirs to influence. 

As for the differences between Fighter, Monk, and Bard- for simplicity's sake the abilities are based on DnD 5e. This is by no means a tabletop RP, but I've found that these abilities are a good jumping off-point for players and myself in navigating specific abilities. 

Lore-wise (and gameplay wise) Bards are very much a support class. They buff allies or debuff enemies through the use of song/poetry/etc. They are capable in combat, but this isn't their primary focus. If someone found themselves really into this idea they could create lore or character specific songs to use in combat. 

Monks recognize that magic is in every living thing, and channel magic in ways that are healthy and constructive. Their emphasis on balancing magic and not abusing it grants them certain enhancements in combat, but isn't exactly comparable to a mage. Monks on the Path of the Open Hand, for example, are excellent in hand to hand combat but also have some self-healing capabilities. Though, as I mention in the original post I'm always willing to work specifically with players for what abilities they'd want to use. 

Fighters are typically an 'every-man' kind of warrior that are capable of using a number of different weapons, but never really excelling at many. Fighters lore-wise aren't trained in any particular organization or army.