Perhaps the proper way to think of it is that all parts of the animals have something that the others do not. A different nutrient, or a different ratio of nutrients. Will you suffer if you choose one over the other? Maybe not. I would assume though that eating from all parts of different animals would be the most likely path to insuring yourself against deficiencies or over doses of nutrients.
In terms of fat, marrow I would put in a different category than all others because it's really quite a different type of thing, being produced in the bones and all and being the breeding ground for blood cells. The rest of fat on an animal is pretty much just for energy or warmth, so marrow to me would be in a different category of fat. I can't point so any specific nutrients, but if I had to choose 2 of the three fats being suet, marrow and hide fat, I would choose marrow and one of the others because the last two are probably more similar in nutrient content than either of them with marrow.
