Those are for earners, bucko, and you ain't earned squat yet.
One of the things I've wondered how to handle in my Lamentations of the Flame Princess game is how to handle the potential conflict between a Lawful Cleric and a Chaotic Magic-User/Elf. I decided not to handle it and instead let the players handle it themselves.
The campaign will start off with the PCs making Neutral Fighters and Specialists. As the game moves on, they can encounter various groups that could, for lack of a better term, "unlock" the demi-human and spell-casting classes. And there may be some other options out there to compete with Clerics and Magic-Users. Just sayin'.
I want my sandbox to be a sandbox where exploration is rewarded in many different ways: treasure, experience points, and even character options. With my method of multiclassing, you'll be able to eventually play a magic-user or a cleric if you can be initiated into their mysteries, you'll just be paying your dues as a fighter or a specialist to begin. Now, once the party unlocks the different options, you'll be good to bring in these new classes and races as henchmen, or start new 1st level characters in the unlocked race/class.
The only thing I'm wondering is how to reconcile the multiclassing with demi-humans. Something to work on over the next month.