
I guess the correct ratio is what suits each individual dog :)
Animals in the wild do not have scales, very true, IB explains it by taking a dead carcass and look at the ratio of bone, meat, fat, stomach contents, offal and muscle that is how we should feed our animals, but it does depend on what suits each dog. I have one dog that gets very constipated if he doesn't get a large amount of veg each day and one dog that could go for long periods without and it never bothers him.
So, do your research and choose what suits you and your dogs.