Considering that "Forbidden Planet" was a major inspiration for Star Trek but featured a caricature of a captain, I can't help but feel that Roddenberry immensely improved this basic concept with the character of Captain Pike.
Of course, a substantial inspiration was the character of Horatio Hornblower. But in the C.S. Forrester novels we could only read what was going on in Hornblower's mind, so the addition of the doctor, the captain would talk to (and thus enable us to learn what was on his mind) was such a good concept that it was kept for Kirk and McCoy.
Which brings me to one question: Patrick O'Brian started his Aubrey-Maturin novel series (visualized in "Master and Commander") in 1969, after Star Trek had aired.
Had he been inspired by Star Trek, i.e. give the captain (Jack Aubrey) a doctor / naval physician (Stephen Maturin) so the audience would learn what was on Aubrey's mind?
That would be something: Pike and Kirk were inspired by a fictional Royal Navy character and in return would give birth to other fictional Royal Navy characters...