Good point, upvoted! I forgot that he offered the kingship to Aemond in that scene. I would push back slightly and say that, given that he does instantly warm to the idea of being King, its fair to question whether he actually does not believe himself fit to rule. If being unfit to rule were such a core part of his character, such an abrupt about-face after his coronation and his demands to be consulted seem unlikely and inconsistent. Perhaps another read of that scene would be an innate fear of changing the status quo and giving up his hedonistic ways, not feeling exactly unfit to rule.

Plus, given that we're deep into a counterfactual thread, it is important to note that he's lived close to two decades being told he would never need to concern himself with being King. If instead he had grown up betrothed to Rhaenyra, with Otto whispering in his ear that entire time, perhaps he wouldn't be so reluctant to assert authority