Many CoC users don't have "kingly ambitions", atleast not properly showcased for now.
Rayleigh is a simple old man who coats ships, and he has CoC, everything we know about him was that he thought Roger was out of his mind when he asked him to join his crew. Oden is one of those men aswell.
You dont need to be like Zoro in order to have CoC, as some people think somehow, you dont necessarily need an ambition to be the "best in the world" at doing something.
What CoC users have in common is:
-Great resolve (which doesn't mean they can't struggle with it sometimes)
-Willing to die for their beliefs in a way or another, doing things that could be considered stupid like:
Zoro letting Mihawk kill him
Sanji refusing to use and destroying the suit who would make him stronger even if it means death.
Luffy destroying the Log Pose, and when he refused "spoilers" from Rayleigh
-Charisma that draws peoples attention, despite if it comes with appreciation, fear, hatred, respect or all of them at once.
-Leadership skills (which is mostly tied to their charisma)
Sanji showed all of that if you ask me.