I'm fine with the restrictions, but I am an old AD&D head. This reminds of multi-classing. Like a Bards for instance, possibly the most overlooked build, but quite useful in many ways. The Bard is just not as good as a full class, but whilst he can shoot a magic missile or 2 and then heal you...then confuse the enemy ect, the Fighter just hits really hard. This class along with Rangers, Paladins were a nightmare to roll, soo many stat requirements.
So is it worth it? Sure if you are planning to build around your character, also realizing early on will most likely be known as the 'gimpy days'.
As far as O.S.'s approach, it seems appropriate. Some class combos could be really beefy, so this makes there reason to roll either way..one may just be tougher early.
