The thing that threw me was when Harry Morrow said
"Jim! The Enterprise is 20 Years old! We feel her day is over."
Now I was never under any illusion that the Motion Picture was 20 years before Wrath of Khan as Space Seed only occurred (according to dialogue onscreen) as 15 year before!
The hiccup on this occurs when you consider that Space Seed occurred roughly a Month or so after the Menagerie in which Spock states that the Talos IV mission occurred 13 years prior to his abduction of the invalided Captain Pike and theft of the Enterprise.
In short, Wrath of Khan seems to indicate that there was no 11+ year Command of Captain Christopher Pike aboard the Enterprise.