He had no Kingly ambition? He’s literally the opposite of all of the other Conquerors. He hasn’t shown a single sign.
Kingly Ambition has never mattered:
Whitebeard nor Oden two very prominent conquerors didn’t have them.
Dude if you don’t think he hasn’t shown a single sign you really need to reread. The signs have been there since his introduction:
1. Sanji would rather die than allow Zeff and his dream to Die - Conqueror Trait
2. Sanji has regularly been able to bring people over to his side - Conqueror Trait
3. Sanji would rather die than abandon his ideals - Conqueror Trait
4. Sanji forced Judge, a character with “kingly ambitions” to kneel before him
5. Sanji attacked a Celestial Dragon despite knowing the danger
There have been plenty hints that Sanji has the will to be a king and likely has CoC.