Yes, Don Bluth was one of the key animators on Fox and the Hound and asked not to be in the credits. Gary Goldman was also a large part of that production if my memory serves correctly.
They're not exactly similar in storylines since in Fox, Todd and Copper are meant to be mortal enemies, and one would naturally kill the other. Can't say the same for leaf eaters. To not join together would be of their own accord.