I can't feed beef, as much as I would like to have it in rotation, they like it unfortunately a couple of them throw it right back up. If you can pick up a can locally to try the different flavors, that is the best way to do it. Frodo is pretty sensitive to carbs also, that is why I switched to the Merrick Limited Ingredient, it is lower in carb than the regular Merrick Pate and it does not contain carrageenan, which can upset some kitties and humans digestion. Also they offer Duck in the limited ingredient if you need a novel protein, and the price tag doesn't sting as much with the Merrick. Hard to feed different foods if they like what is down to eat. I keep everything under 5% carb so if Frodo and now Pippin (adopted him about a month ago from vet, no one wanted a diabetic 9 year old, oh well their loss our gain), get into it I don't have to worry. Pippin eats pretty much anything, Frodo is very picky and even more so since he was diagnose with HCM and congestive heart failure. I wasn't fond of all the vegetables in Wellness, even though that was the first food I went to from dry food, but moved on from there.
I understand the food obsession, I drive my husband crazy looking for different foods. He swears they eat better than he does.. LOL. So far the Merrick Limited is holding steady for them all, the 2 that eat Hound & Gato and every now and then I through in Fancy Feast Turkey & Giblets or Kitten Turkey to break the monotony, along with Tiki Cat chicken.
There was another brand I tried you might want to look at Wild Calling, they have several novel proteins and very low carb. Rated very well on Chewy. I might have to give them a try again myself

come to think of it. I would like a different protein, and duck is hit or miss one day to the next, but they do have Buffalo, so maybe..

who knows..