12 allowances each, presumably to run 12 quests each? Can't be done. How do you account for players with only the first rank unlocked, without access to 12 different quests?
Also don't really see a huge benefit to players leveling extra jobs, unless they have those jobs at wildly different levels. ARR quests are pitiful enough (and deserve a buff), but after 50, they're basically useless. HW quests are similarly useless after 60.
Finally, the time investment. Trying to do 12 quests for each beast tribe in some misguided "catch up" effort? That's soaking up an awful lot of play time.