Objectively speaking as the one who doesnt has any favorite among them :
In the end it depends what kind of battle I just see them gonna win and lose to each other in turn,
since if one of them stronger than the others they wont be annoyed at each other, like understanding of your own skill, mihawk no matter how you provoke him he knows its silly to argue to people weaker than you,
kizaru however while zoro and sanji indeed very strong unless the plot need them to defeat him I still think its too early for them at least not currently not when zoro hasnt defeat mihawk, we never see kizaru in full power yet and 3 admirals supposed to be balance 4 yonko power and 7 shichibukai and mihawk only one of them, even aokiji so strong that blackbeard know he didnt treat him badly and he defeated the old garp, so it was a bit weird to say he is under them for now its too early to say when they dont fight him easily as you can see it egghead,
they do have potential to defeat him if there's circumstance but claim them stronger just wont fit as it'll be probably hard battle to win, If that's not the case and one of them stronger than kizaru then he has been slayed already in egghead, that's oda storyline to tell you if the character not strong enough to go up against
However according to the original post statement zoro more closer to luffy is more supported by the fact that zoro has conqueror too which is a whole different meaning in OP world based on strongest people, and the fact that he despite not a captain a part of what they called "worst generation" further enhance this statement, plus sanji inability to fights with women also not help as favorable points in objective ranking that is the conclusion despite them having ability far superior than the other in certain aspects.