Basically, there should be some classed that everyone can go for, that will deal sufficient damages, easy to understand, but that got limited power -> easy, but not abusable by old players, that should go for something else more rewarding. These classes in history, normally were either pikeman/spearman or persons with bows, crossbows, or with throwing weaponry, affordable for everyone (ok, not for the crossbow part, a peasant cannot afford an arbalest), and extremely simple to use, in all cases (what is hard in staying behind real melee players to give them support and cover ?).
How to make it rewarding for new players and non abusable by old ones ? Don't know at all about that. Some builds, with high level, tend to become extremely over powered (either some insanely fast guy, dealing utterly retarded damages because bonus speed, or some 27/21 build, one hitting people and tanking everything).
Ranged should be some kind of rewarding for new players because a lot of players played this class in native, it's THE meta class you played in singleplayer/multi at the beggining. To illustrate, in cRPG, throwers got low ammo, but should deal normally huge damage (taking a jarid in the head shouldn't let you alive, come on...). Everything should be done with this class to be playable by new players, but ... atm, it's expensive, heavy (retarded weight on stacks), and "eats" your melee ability, unless you're high level. The fact throwing was historically very used in armies by peasants is explainned by the simplicity of the work : you come, you throw some lances/axes, and you charge and die for your motherland. Simple, but quite limiting compared to archery and crossbowmen, that got more durability, shooting from far and staying in safe zones controlled by the team, and aiming skill is setting the skill ceilling a bit higher compared to throwing, since you know you won't 1 or 2 hit kills quickly (with arbalest, a missed shot can be fatal, with a bow, a missed shot is almost nothing, but you need more than 4 arrows to kill the medium armored lad nowadays).
About spearmen, make it forgiving (increase the landing zone of stabs maybe ?), but buff the other melee classes at the same to avoid that a lot of old players go for these classes, that are less rewarding than shielder, 2h, polearmer, etc ...
TLDR : Reduce ranged's weapons's price (make it affordable in this order : throwing, archery, crossbows). Then, buff throwing damages and make it more randomized (if you have aiming skills, you'll go archer or crossbowman), and buff support melee classes in a way or another (reduce greatly the price, make stabbing a bit easier to handle, and increase the variety of 1d and 2d weapons, put some with low price filling their own niche), but buff all damages of melee weapons to avoid having a shitload of pikemen and spearmen.
I believe it's imperfect as hell, but I think it must be reflected on, particularly on the melee part. Oh, and sorry for the wall of text, but nothing is simple anymore.
