We shouldn't want Kirk to be batshit insane as well, though. And that's what we get if we pursue the idea that he believed himself to be an important eyewitness to who Kodos was.
^ Kodos was referred to in dialogue as Governor. That's all the proof I need that 1) he really was a Governor, and 2) Kodos was his real name.
Why should that follow? Obviously, he would be both "Governor" and "Kodos" at the time he committed his atrocities, but that's all we can learn from this.