I think we all need to take a step back and understand that beyond Elbaf there may not be room at all for direct 1v1's anyway unless you are the final villain.
There is a war coming, it will very obviously involve most of the people here, thats where the Marines will probably be fought:
What people have to get over is the idea of clean 1v1 matchups. A lot of these people (at least their subordinates) may go down in big groups or huge scenes that dont necessarily involve the crew).
Essentially, dont be surprised that even if the Monster trio fight Admirals, Yonko/YCs, etc, many Zodiac VAs, God Knights, Gorosei, RHP Commanders, CG members, RA commanders, or BBP Captains go down by the crew or a combination of
- The crew beating someone
- Another enemy beating an enemy (i.e. Mihawk one shotting someone important; Blackbeard killing Shanks for you BB nutters, Dragon fighting Imu and losing, etc)
- A combination of things that happen between multiple people causing someone to lose (i.e. Shiryu being a dick and harming Fujitora before Zoro or Mihawk defeat them, just guessing)
Its going to complete chaos imo, and not as clean as people think or want. EVERYONE will probably salty in their own way when it happens lol