The more I think about it, those early saying we will get a spread of the allies together standing next to Luffy against Fujitora sounds about right. It's been established that they owe the Straw Hats an eternal debt, but the most we've seen at this time has been the various allies spread around. There is also the fact that while helping, we've yet to see them really follow Luffy's lead. Here's how I see things going down before we get the spread that gets Fujitora to back down.
Everyone else seems to think that because Fujitora is an admiral, he is unbeatable. We get this feeling when Bartolomeo and Sai express their feelings about Luffy trying to punch Fujitora. Even for us readers, we have yet to see any Admiral have to give a whole lot of effort except for a few snippets during the war. They watch Luffy as they feel he is insane to take on such a monster, that it is impossible for someone like him to beat an admiral, let slone survive against one (much like a number of readers believe). So they watch as a barely recovered Luffy fights against Fujitora.
Luffy manages to land some blows and cause some damage, and slowly minds start to change. Bart, being the biggest fan of the crew, loses his shit and starts cheering. Luffy is tired but still goes at it because he can't run away at this point. Running away would be like Zoro showing his back, a shame and shows that he can never be worthy. As he continues to push, the other allies realize that an Admiral isn't invincible, that they are human like anyone else and can get hurt. The fact that Luffy, one of their saviors, is doing this gets them pumped. They decide that to honor their debt, they will forever follow him.
Luffy, now getting clearly exhausted, is facing against a still relatively fresh Fujitora. He's getting ready to take down Luffy when everyone is standing behind him. Weather through body language and/or speech, they show that they are 100% behind Luffy and are his allies. The spread is everyone who contributed to helping fight against the family, which is the first scene where they are all together. This will give a small idea of what to expect later on when Luffy's alliances come together with all their power. Fujtora, while still overall healthy (but now being affected by Mansherry), decides that taking all of them on would be foolish. From there, everyone is able to leave safely, which afterwards a party on the ship celebrating being allies and how awesome it was to see an Admiral back down for once.
It's definitely not time for Luffy to outright win against an Admiral. However, it is time to show that these previous "invincible" people are capable of being pushed back. Unlike where everyone was so weak or lacked Haki that they couldn't be harmed, they can't just go around taking down everybody. It shows that Fujitora is still strong, but that with enough power against him, he will have second thoughts. It's the best possible option at this time to show off both sides. Next chapter will give insight if this is indeed how things will go.