??
Zoro was pursing WSS, already had made a name for himself on his own and had more infamy than Luffy in EB, had some dudes following him, and killed Mr 6 (IIRC). By the time he joined up with Luffy.
And said to Luffy to his face that he would kill him if he stood in the way of his goals.
Nah it isn't. If you think it's 99% agenda driven, it's probably based because you've been playing in the agenda mud for too long lol.
I don't think it's agenda driven, but factual, to argue that Oda himself has played into the persona and ambitions of conquerors several times in the series. But he also isn't playing into this line of thinking a 100%, Koby is a great example here.
This was my take on the topic in the spoiler discussions.
It's the persona and ambitions narrative that was used by those who pushed Zoro to have conqueror's haki, not parallels or anything; this was before there was even any direct powerscaling implication here (for a decade+ conqueror's haki was simply fodder control and just indicated potential).
Just to address the OP meanwhile, Jinbe and definitely Ussop of course shouldn't have conqueror's haki. Jinbe is a 46 years old veteran, too late for that. Ussop especially having it would be dogshit writing and kill the entire thing, might be a drop worthy event even.
Coming to admirals.
It's a case by case basis with admirals. I'd say Akainu, Aokiji and Fujitora would be in sync with the "persona" narraive as well. While Kizaru is a mixed bag (leaning towards no for me), and Greenbull is heavily leaning no.
Issue is that there is no indication that any admirals have it, so far. That should however not be used as a confirmation that admirals won't or can't have it obviously, esp the 3 I mentioned above.
And there is a powerscaling argument also here, in that admirals have such insanely powerful DFs that they don't need advanced conqueror's haki to reach top tier as well, but that has zero relation to the persona arguments of course.
I'm not a fan of Sanji having conqueror's haki either, due to the persona narrative. Nothing to do with powerscaling, Oda can always upgrade his fire powers and exoskeletons as needed to made Sanji close to Zoro in power.
However, if Koby can have conqueror's haki (it isn't 100% confirmed yet but honesty impact might have been advanced conqueror's), I see no reason Sanji can't.