I have no issues with the Enterprise being 40 years old in TSFS. We are forgetting Capt. April. Captain of the Enterprise before Pike.
I wasn't forgetting April at all. I was just using only on-screen evidence.
Though if we count TAS (which I only do about half the time, as I'm not as familiar with those stories) I suppose I should have included him as he was featured in (IIRC) "The Counter-Clock Incident."