We felt that the near-mandatory buffs were Fort, Kings and perhaps Gift. It may be very hard to do say a 10-player heroic without those buffs.

Once you get into Arcane Int then you have to start thinking about Spirit and Shadow Protection and whatever. We didn't want to create a dozen or more new scrolls. And honestly, we'd rather you have players than scrolls. But we recognize that you don't always have that much flexibility in a 10-player run.