Hi, though it is from the same company, the flavors by Merrick really do vary. That said, I know we have one member who deliberately rotates the flavors she offers as her cat does get bored after a bit, and this is how she keeps him happy and eating
I would not personally try a new flavor every day - but pick two or three to try for the next month, and then next time you get Merricks, maybe get the favorite of the flavors again, plus one or two new flavors...so you can gradually, have your kitty try all the flavors.
Consider serving one new flavor for a week, to be sure if there is a reaction, you know it's to that flavor, and not because you tried 2 to 3 new flavors in the same week.
just my 2 cents!