Hi Stephanie and sweet Tobey and siblings. Your question is a good one and the most basic answer I've found in the last year is that
the low carb wet foods my kitty will eat consistently is what we buy. Radar was a dry food grazer for most of his life but when he learned that meat could be in his dish, he never looked back at kibble again. It has been quite the process at our house and I've thrown a TON of cat food away in the last year. I never had to think so hard about giving him kibble... just pour and walk away.....but the wet food options are so voluminous... it's overwhelming.

I'm happy to say that after extensive experimentation we now have a decent rotation that I'm satisfied is providing the proper nutrition for the FD situation AND, more importantly, meets the requirements of the fuzzy one.
Here's a few tips to consider as you move forward with trying to find out what your crew likes and doesn't like...
1. Consider the consistency of the food - Radar prefers pate style foods rather than chunks of meat. It must be easier to lick up and swallow...

2. Once you figure out something about what the cat likes to eat, know that the preferences can and do change... sometimes several times a day. It goes something like this - Radar will eat Tiki Cat - except when he doesn't want it. He really really really loves rabbit and will eat it always - except when he is tired of it. He really enjoys fish - except for those days when he doesn't want to eat it.
3. Sometimes Radar needs a little encouragement to get started -warming the food to a nice "warm mouse" temperature - a few seconds in the microwave - can really help.
4. Sometimes what Radar wants is to have something amazing sprinkled on top of his food - try Bonito Flakes or Pure Bites freeze dried chicken pulverized into chicken dust.... very popular additions at our house.
Good luck figuring out what they like and try not to drive yourself crazy while experimenting...