One of my dogs is allergic to chicken. I have to test other fowl to see if heís also allergic to that. Iím trying to keep it as simple as I can. If it gets too complicated or I canít find ingredients, it might not be possible to do this.
My view: The KIS (keep it simple)method. If you are planning to use THK then really all you need to do is add raw or cooked meat. THK has done all the other work for you. Acquiring beef isn't difficult. $$$ yes compared to poultry but doable.
I really feel that what makes raw or home cooked diets so intimidating in the beginning is the overwhelming variations of the diet itself. Prey model, franken prey, premade complete, base mixes, dehydrated, frozen, fruits and veggies, no fruits and veggies and on and on.
Add in food/health issues and it can quickly become a quagmire of information needed and choices to be made. Or lack of choices (which is my case). If my dog didn't have sensitivities to almost everything and a gut so stinking sensitive and a host of other issues I wouldn't be feeding raw. Not that I'm against it, just that it was mind boggling in the beginning and I was so worried of doing it all wrong. And truth be told in the beginning I'm sure I did it half wrong. I tried it all and spent a ton of money. Over time with lots of trial and much error I finally realized the simpler I kept things the better the results.
It sounds like you are basically trying an elimination diet to hone in on what is causing the health issues. If your dogs like and will eat THK base mix then I personally feel that is the easiest most effect way to go as a trial and guarantee nutritional balance. If it works out you have a simple meal plan that doesn't require a ton of meal prep, storage space or mind numbing thinking. With true full raw if you still had issues you may have invested in a freezer, a lot of meat and a bunch of supplements just to get started for a diet that didn't pan out.
Now with all that said if THK and raw meat works and you want to venture into going full raw to possibly save on cost down the road the transition would likely be much easier.