Scenarions:
One(without Gorosei)
Luffy and co face Kizaru, Zoro and Sanji clash with Kizaru but Luffy truly get his one vs one later, he beats Kizaru or the fight end in a draw with every fractions leave the battlefield without losing(except CP0, these guys are fucked up).
Two(with Gorosei)
Luffy and co face Kizaru and Saturn(arc boss) and the navy. Since Saturn has the control over Seraphim, he take the lead which push Strawhats vs Seraphim.
Luffy face Saturn 1on1
Zoro and Sanji fights Kizaru
The strawhats win or fight end in draw, if not Saturn wins his battle and also Kizaru defeats Zoro and Sanji, strawhats lose the first big fight against the End of story villians, Vegapunk dies.
Lot of scenarions can happen, but if Luffy is about to lose to Saturn, I can see Kizaru also beating Zoro and Sanji.
Either Strawhat fandom will take good hype or Navy+WG will get the last laugh of this arc.