Uh, no. Flag rank is entirely political. Time spent coat-holding for a Senator or senior civilian official counts for a lot more than combat efficiency.
There is an old saying that the best officers in the military are the O-6's who never made O-7.
Things must’ve changed since I left then. The nicest people I ever met were O-9s and O-10s and my warrants. At that level you have almost nothing to prove to anyone and you ain’t going anywhere. Afterwards I worked for Al Haig, who has some of the traits you speak of but was also a combat commander. He would’ve made 5 stars if they were still doing that in the modern era.
“There is an old saying that the best officers in the military are the O-6’s who never made O-7.”
That was my Dad. Fifteen years in grade as an infantry colonel. Every OER said promote this officer immediately to brigadier general. Two tours as brigade commander. Five Legion of Merit awards & retired with the DSM.
But Dad made one mistake: in 1965 he came to his three-star boss’s defense when the latter was savaged by Sen. Ted Kennedy in a committee hearing. Dad followed Kennedy to the VIP elevator and turned his ears bright red according to his grateful boss.
Word filtered back: “No g-d d—ed chicken colonel talks to ME like that and gets away with it!”
So I think that saying is largely true.