Tbf though, chapter 957 still has Fuji talking to Akainu on good terms and discussing how they should put their faith in the Seraphim. This all comes chronologically after everything we just read.
Fuji is absolutely still against pirates, and I think Fuji would fight Zoro in the same vein Mihawk woukd fight Zoro. They arent bad people outwardly, but circumstances just out them against one another (the latter being more obvious)
I think there’s quite a few things that distinguish between Zoro vs Mihawk compared to Zoro vs Fujitora.
Firstly, Zoro and Mihawk is obviously personal, to fulfil a promise that goes back since the early stages of the story. There’s now also the potential- and I think it’s almost a cert- that another wrinkle will be added by Mihawk genuinely wanting to make Buggy the Pirate King. Zoro vs Mihawk will be a fight for both themselves and for Luffy.
That doesn’t really exist for Zoro vs Fujitora, their interactions are far less weighty. Sure, they can fight, but it’s much in the same vein that Zoro
could fight Beckman, another good man who would just be opposing Zoro. Zoro vs Mihawk has the personal reason and the wider reason, Zoro vs Fuji is just the wider reason.
Secondly- Fujitora is a better man than Mihawk is. Mihawk isn’t an especially nice person. He’s not a bad person, but he’s never done anything we would consider overly heroic. I think the only kindness he’s ever shown is letting Perona stay on his island. Just go back to the fight between him and Zoro. He basically launched an attack that had every chance of killing a nineteen year old just because he had the feeling Zoro could survive it and make something of himself. He murdered a hundreds, maybe thousands from Krieg’s armada because they annoyed him. Bad men, but that doesn’t make what he did any better. I don’t think you’d catch Fujitora wiping people out for fun.
Then there’s the organisations they joined. Fujitora joined the Marines, that has lots of good people in it, lot of bad people, but has tried to do good things inside it. He’s shown he’s not a black and white, pirates bad marine good guy. He helped the RA, and he can tell Luffy is a good person.
Cross Guild are not really all that nice. Crocodile is an awful person, Buggy is not much better. Their Marine bounty plan is not portrayed as an especially good thing for the world, in fact, it’s making it worse and more chaotic.
I disagree that Fujitora is against pirates. He was against the Warlords. That’s what he says in the scene you reference. If he was against pirates then Luffy and Law would have been in jail at the end of Dressrosa. I think Fujitora can very much distinguish between good pirates and bad pirates.
It is essentially a very hard sell for a man who has said this about the hero to be a real opponent to any of them
Note that Mihawk doesn’t give a shit if Luffy or Zoro is kind or not. He is interested in their strength and to see how high they can rise in the world.