There is no best.
A raw food diet with 10% bone can really make some dogs do well.
Meat enzymes affect teeth too. For the better.
I'm no fan of corn t o feed a dog.
Many current grain free offerings have peas in them. What do legumes do for/to canines?
Even with better brands (and better brands can and do change formulas and suppliers ect..) they lack things your dog would benefit from. Taurine perhaps...Or a trace mineral missing.
By changing brand or formula at intervals (gradually by blending with prior recipe so not to shock a digestive system) the gamble of picking up something missing from the previous formula might be gained. But ingredients need studied regardless.
Ask your vet what your dog needs. (not saying the vet will be spot on ,but you can research to see what gets confirmed.) Not in a brand , but in food itself.
I raised a breed for a decade and had other dogs all along.
While a raw food diet appeals (there are sources for interesting ingredients I'll not dwell on ,but lacking space for a chest freezer is one excuse for dodging such a diet.
And clean up after feeding raw when I have adds up with lots of dogs involved.
One thing you might consider for starters in a food choice after determining it is food good for a dog vs good for the manufacturers pocket , is what protein level suits your dog. Then the amount of fat.
Older dogs and less active dogs don't benefit from a high protein diet usually.
And in some cases it can be harmful.
Keeping a good weight on your dog ( vs overweight )matters over time too.
Consult your vets opinion of course , but green beans can be a good filler.
Whelping *****es we cook up meals of white rice , mix with boiled and drained hamburg and add a generous dollop of cottage cheese.
Easy on the belly . Digestible a bit faster , and keeps weight decent.
A dog chewing it's feet or licking them alot without a yard or home or injury relationship can be showing signs of allergy to a diet.
With lots of dogs being fed the same diet among their numbers it is not unusual for one to have an issue with a type food, that the others don't.