Zorobros are so much into this "Zoro level headed" and "Vice captain stuff" that what he says doesn't needs to make that much sense or have an actual payoff, it just needs to somehow look cool
Even if Zoro is proven wrong or isn't shown taking a good look at the full picture
He is trying to arguably avoid unnecessary trouble for the crew, this is fair and very reasonable, but it doesn't go beyond that. He is saying he has "faith on Vivi"... like... Ok, fine, but how is this supposed to be something "level headed" when he is relying on abstract terms? Having faith in Vivi, who can probably get beaten by a Gifter, means he is being smart?
All they know is: Sabo didn't killed Cobra, someone else did.
Why should they even believe Vivi is ok? Having faith is actually the only thing to do here if they aren't willing to go help her, and thats all
Sanji was also extremely worried in WCI about a lot of stuff, and those stuff influenced his decisions, until he had nowhere to run anymore, ending up in a break down and accepting that things would need to solve themselves in a way or another, even if the whole crew died in the process without Sanji not being able to sacrifice himself to keep everyone safe (not just the crew), as he would prefer to do previously. Zoro was never forced to do that or put in such a situation that drained so much of him mentally speaking apart from the usual obvious consequences of dying in battle against an enemy that everyone in the crew may suffer from. Even in Kuma's situation, Sanji was there to do the same thing, and afterwards he reassured that Luffy and nobody else knew about Zoro's sacrifice in respect to Zoro.
Im sure that these same guys that used to talk trash about Sanji because of his worryings are the same ones trying to convince Zoro is a genius and "vice captain" for that one. Mind you that Zoro is in an extremely more favorable situation, with no actual pressure, death sentence or responsability feeling for someone elses decisions and lives, unlike Sanji was in WCI.
It would be easier for Zoro to say: "Dude we can't live other people's lives, even if they are our nakama, we can't control everything that happens, so we shouldn't get into huge trouble for that matter"
Curiously, im sure that if Sanji said something like that he would be called: a pussy, coward, weak, doesn't trust his captain and his crew, didn't learned anything from WCI, doesn't cares about helping his nakama, he is selfish.
But since its Zoro, the "Zoro is the official Vice Captain" boys start jerking off each other and trying to convince everyone how much of a brilliant Vice Captain Zoro is.
And thats why Zoro and Sanji are the wings. While Zoro has a more cold headed approach to some situations, to the point the crew gets shocked for his apparent lack of empathy and get mad at him, Sanji sometimes brings up the more emotionally driven ones, and both are extremely important, balancing each other.
In Usopp's case for example, while Sanji was the one that convinced Nami that Zoro had a good point, which settled the deal about Usopp's possible return to the crew, he also helped Usopp regain his self confidence. He saved him in the Sea Train and convinced him to not give up but to help Robin because he could still be very useful back in EL, despite the flaws that everyone may have.
The only reason Kinemon is alive and Wano happened lies on the fact that Sanji decided to go all out at helping Kinemon, simply because of the empathy he had towards him.
And im sure Sanji agrees with Zoro here, just like he does almost the whole time when the matter is keeping the crew out of unnecessary trouble.
All Sanji said was "Please be safe!", he hopes Vivi is doing fine because he likes her that much, but he knows he isn't in a spot that makes him be able to do something about it. Other than that, Zoro and Sanji insulting each other is just their regular routine.