If you were switching foods often and giving them many choices, that may have made them picky. They like Chef Michael's b/c they spray animal fat on the food and it entices dogs. I feel your pain, but I would not stick with this food.
Try to better food (Blue Buffalo, Acana, Orijen, Fromm, Wellness. GO! etc) and stick with it. They may strike for a bit, but chances are they will come around and eat. Once they realize that the one you choose is it, that you will not be offering something else b/c they turn their nose up, they probably will eat.
We had our finicky Snickers and he did well on Acana. But now he is on a premade raw diet (Primal) and it is just perfect for him and our new puppy Reesie although Reesie is a trash compactor and would eat anything!!!!
Good luck-
Viv