Also AH pricing isn't an issue either; you can make it stack without the AH having to sell stacks.

Same for Beastmaster food; you could have bags that stack to 99 that hold 12 each and not sell them on AH (and if it really matters, make them exclusive if bazaaring them would be somehow evil for the market). Beastmasters would buy them in stacks of 12 from crafters and then bag them themselves for easier usage of petfood and possibly even jugs.