I define mashing classes as someone without a mage base having some sort of sub class like necromancer. Some classes are innately part of it like Paladins generally have low level magic but its heavily based in the divine/holy category. As I said you can't take a mage class if you are a rogue, and warrior already. Same goes for any variation of the aforementioned. You get two bases if you pick say a rogue, and a mage you don't get to be a warrior.