@Gia:
The problem is knowing how Oda sets up battles based on past arcs. If we ignore WCI for being unorthodox, and compare it to things like Enies Lobby/Dressrosa, Oda could spend upwards of 20-30 chapters just moving the main characters to their battles, explaining Kaido's past and doing a bunch of skirmishes that don't lead to the end of certain characters. Could it be the next 3 volumes? Maybe? But I'm at this point that we are at a few volumes away from actual conflicts. Of characters going head to head.
Compare it to DR: from the beginning of Birdcage to Laws Past was 17 chapters. It took nearly half a year for Oda to place everyone at or near their respective fights and do skirmishes. Then he took another 25 chapters after this to for finish Doflamingo and his crew. Wano is over 3 times the size of DR in terms of characters lol. By this time (71 chapters in), Machvise and Lao G were defeated and we were just getting those 2 covers that had Doflamingo's family vs. Luffy's crew and Fleet. Tbh, I don't think we've even reached the "Birdcage" moment of the arc yet. Oda still is introducing Beasts Pirates and needs to characterize Kaido and his crew much more before things get hairy, and they will eventually.
If I was being ridiculous, I could see your 3 cover idea starting around vol 100 or 101. I think people severely underestimate just how much more setup Oda will do before the actual battles begin or finish.
Just my opinion though, could be wrong, we gotta wait and see how 97/98 content pan out
I don't love the idea of being so clinical about it, saying "well this many chapters into this arc this had happened." Whole Cake Island demonstrated a huge willingness on Oda's part to break from his most successful formula, and the five-act structure Wano's going for suggests it's not going to be quite like its contemporaries either.
We've already had a lot of shuffling and skirmishing in the opening acts. Oda must know how eager people are to get to the action. Give it the rest of this volume to establish the Tobi Roppo properly and introduce the Numbers (assuming they're going to be something a bit more monstrous and won't need the same level of character stuff as other opponents) and I think we can start getting to the meat of things.
I doubt we'd get another flashback positioned like Law's, right before the climax of the fighting. Not so soon after Oden's massive one. I see Kaido's story as something we're more likely to fade into as he falls, finally getting that defeat he was waiting for. I wouldn't want to see the past again until the end of the arc.
I do think you're right that we're still minus a Birdcage moment thought. There's at least one big development still to go to put the endgame in order, probably coming right at the end of act three.
But yeah, all a matter of opinion until we know better. I've been pretty wrong about this kind of thing before. Hell, I thought Wano was going to get right to the action and undercut everyone's length expectations when it first started. How wrong I was about that lmao