Considering Luffy is encountering an Admiral, at 2 formidable Yonko exist, plus a remaining Fleet Admiral and the hidden ruler of the WG, i dont get how this can bw stated lol.
Then theres just the concept of Rocks, the Burned Man, Weevil, etc all still unadressed. What do you mean by substance?
Everybody from Roger's Era or before is just movie bait. Out of the dozens of notable fighters that kaidou and big mom have plus their allies we saw the strawhat fight about 10 and a few of those were just skirmishes. There's two main enemies left. Blackbeard and the knights. Shanks, imu, moria the cross guild etc won't get much more than a few panels dedicated to them. Shanks maybe three chapters at most and imu ten at the most. I don't know if luffy is going to stay on egghead or not but elbaf will just be a staging ground for the final battle. The man with burn scars is either going to be kidnapped or team up with the wgand or blackbeard. That's 25 chapters on elbaf where luffy gathers his troops 16 chapters of somebullshit mini arc that will extend to 20 chapters of setup where luffy gets seperated.. 30 chapters of war 7 chapters of Imus back story 2 chapters of luffy on raftel and a single chapter of luffy giving his hat to Shanks.
100 chapters at most how I see it. Maybe more if blackbeard vs luffybis it's own fiasco and not part of the final war at mariejoa. Blackbeard is going to pop up at elbaf or what ever island is after that.
On the off chance that Blackbeard is still around after Luffy overthrown the government blackbeard will fight luffy somewhere near rafter. Other Than blackbeard and aokiji the blackbeard pirates have no depth and have already been defeated mutiple times. Oda won't have more than 15 chapters for them. If it's like the old days one chapter per fight and more for blackbeard vs luffy.
Panels explains who Pizarro is
Sanji vs avalro Pizarro - one chapter
Chopper vs doc q (the fight maybe dome panels )
Franky vs vasco shot ( alcohol vs Cola)
Hilarity ensure 1.4 chapters
Usopp vs van auger- maybe 2 chapters since usopp has so much internal conflict
Robin vs San Juan wolf ( showing that her abilities truly do bypass physical strenght)
Nami vs Catarina Devon- one chapter. Maybe nami blows her into Hancock who turns her to stone or again. One chapter.
Zoro vs shriyuu one chapter
Brook vs Lafitte, jenbe vs jesus - one chapter. Well get 80 to 130 chapters approximately and oda doesn't care about other plot lines like krieg or Florian triangle or shirahosi/otama.