Hate Oden, so hard yes on him not existing lol. While I understand that Oden is a pivotal character to Wano gosh I hate him so much. Like I do hate Sommers atm, but Sommers is meant to be hated, so we're cool. Oden on another hand.... ugh. And I also don't really like Momo and don't care much about Hiyori. Now I am probably treading dangerous waters because I actually like Yamato (minus the Oden gag) as I like the trope of child of evil character being on an opposite side and helping the heroes (think Zuko from Avatar in later seasons), but her Oden fangirling was annoying af. The only scabbard I kinda liked was Kinemon. The rest I don't care much (although I still think Izou should have lived and Kiku should have died).
So, if I was writing Wano, I would:
- remove Big Mom
- remove Oden, his family and scabbards save for Kinemon (Kinemon might be looking for help outside Wano to overthrow Kaido as he understands he has rebellious forces but they aren't strong enough)
- remove Zou connection
- minimize number of supernovas present to give more time for SHP to shine (since I don't care much about them, I would probably just leave Law as it's kinda cool continuity from PH, and I sorta like X Drake with his failing his Marine plot, but I am open to other suggestions)
- have Zoro explore his ancestors
I like the idea of Wano being a closed-off legendary Samurai land being under oppressive rule of Kaido, and honestly I didn't ming Orochi that much other than the fact that he was super underwhelming power-wise. I would be fine if the plot was more similar to Alabasta, where Luffy helped Vivi and her dad overthrow Crocodile, and here Luffy would have helped Kinemon to overthrow Kaido (would be also interesting to have good and evil royal brothers dynamic with Kinemon and Orochi, like both could inherit the throne, but Orochi would betray Wano for Kaido). Yamato could've been a secret trump card helping SHP and Kinemon in fighting Kaido.
Alabasta also had a ton ton of characters, but it still had enough focus on SHP, and this is one of my main critics for the post-TS OP, especially starting from Dressrosa, when the number of characters was starting to go out of hand and Oda had to split SHP to focus on some of them at least a bit
Not saying my version of Wano would've been better in the end, but it would totally have less characters and cleaner storyline. Kurozumi were born to burn line still leaves such a bad taste in my mouth.