I understand where they are coming from, Swen probably tried to mix two classes equally (cleric 6/ wizard 6 etc). It is a legitimate improvement in those cases and I could accept it. But it becomes more and more ridiculous the more asymmetrical the two classes are (sorc 10 tempest cleric 2 etc)
Multiclassing should be a bit of a hidden feature, mainly accessible for people who know what they are doing and are coming at it with a mastery of the game systems and a plan for what they want
