Scooting? I would check either for parasites (which can also cause pudding poop).
IMO, since Fromm is a pretty good food, it is unlikely both dogs are having issues with the food. And if they are, it may not be the same ingredient affecting both dogs. There really isn't any definitive way for US to pick an ingredient.
If you really feel it's the food, try a LID food with only a couple ingredients like a fish and sweet potato.
Jax Von Monkeybutt, CGC
Queen Banshee Boo
Sierra the Undecided
Cracker, The Great Shedder
Rich N Handsome, "Red"