Oh, I deny it, alright.
First of all, there are way, way, WAY too many four-stars for the size of our armed forces - men and women, both.
But to give an officer whose surface warfare commands were, to put it mildly, minor such a distinction is ludicrous.
The Vice CNO from 1942 (when the billet was created) to 1945 was a three-star, and if three stars was good enough for a 2500-ship navy and 6 Marine divisions, it is CERTAINLY good enough for now.