I don't agree with racism either (ie: certain races can't be certain classes). There should just be heavy attribute differences between a Dwarf rogue and a Minotaur rogue.

Now, I know 24 classes looks like a lot, but that's only if you plan on evolving one class from 0-50 or what have you. The way 24 classes at end-game can work is using a web system. I somewhat broke out the 3 webs in my last post. Basically, everything in the top block (Ranger through Assassin) starts out as a level 1 "Tracker". Everyone who wants to be one of those end-game classes will be a "Tracker" until level 10 when you have to do a series of quest and make choices from which you will decide if you want to go to Archer, being more of fighter style of a tracker, or if you want to become a Bandit, being more of a theif style of a tracker. This would take place again for both the Bandit and the Archer later on down the line and then once more from whatever class they develop into. Here's how one would become a Ranger for example. Tracker - Archer - Woodsmen - Ranger.

What this does is allows for tons of end-game differentiation which is lacking in most games while at the same time not watering everything down so much because you have to think of cool spells and abilities for everyone from level 1-50.