Here is the massive wisdom that I gathered from my headcanons:
Oda will first start tying up massive events that involve many characters. Why? Precisely because there are too many of the allies/enemies and too little time to focus on the main cast in such a setting. That's why, I think WG war will be removed from the table first.
After that massive war where he has to focus on an unparalleled amount of allies, he will focus on the most important core crew battle in the show against Blackbeard pirates. This is a 10vs10 crew battle where each Strawhat will show everything they got combat-wise and also possibly some of them will have their dreams accomplished in these battles. Every SH member will get their 5 minutes here.
Following that trend, Oda will continue to scale down and this is where Strawhats vs Cross Guild will happen. Where is the scaling down you might wonder... Well, this is not a full crew battle, this will be Davy Back fight, 3-round battle, scaled down from 10-round battle we had against BBPs. The battle between triggers, Fame vs Fame, Power vs Power and Wealth vs Wealth. Power vs Power is opviosuly a fight between Mihawk and Zoro. The other two may not be a regular fight type of rounds, as it wasn't in previous DBF either. Nami will have to face Crocodile in some type of game and she will lose, narrative requires it. Zoro will make it 1:1 and Luffy vs Buggy will secure a 2:1 for Strawhats. Buggy is a gag? So was Foxy and he almost beat Luffy in DBF. Buggy will force Luffy into a game where he stands a chance at winning.
Down from the 3-round battle we go into a solo battle between Luffy and Final Villain that is Davy Jones.
All according to keikaku.