Its already a 13 chapter flashback, and Xebec has many awesome panels. Its like this because theres too much to address.
Personally Id wait to see the full picture, but the way Ive always taken this series is to not set yourself up to expect more than what has been done beforehand.
Oda doesnt spend a large amount of time drawing fights in flashbacks. In fact this is the most he's ever done in one event behond big name clashes.
I'm not strictly talking about fights tho, that was expected, I'm mostly talking about interactions and appearances OUTSIDE of Xebec, Roger, Garp and the OG Emperors.
- Gloriosa and Stussy arrived on the island and then went MIA. Gloriosa even had a build up for meeting Shakky and possibly have an assist role in her rescue.
- The Knights of God grouped together, after that: MIA. We didn't even see them in the background. Maffey was the only brief exception.
- Bogard is another one. Shown arriving on the island and running on Garp's side before reaching Imu's position, after that... MIA.
I could continue.
Now I know those are a lot of characters to handle for a flashback, but to increase the sensation of how heavy and out of the world the God Valley incident was, all Oda needed were little things here and there. I can give you some examples:
- Briefly show Gloriosa covering Rayleigh while he's carrying Shakky, maybe with a quick exchange of words between her and Shakky.
- Keep the infighting between the Rocks Pirates by having Shiki and Axe clash with each other, right near John and Ganzui. Good way to show how things are escalating.
- Show a couple of God Knights dropping pirate bodies left and right. A matter of 2 panels that rafforces their presence as a factor in the conflict.
- Have Bogard do... something. Even just a cool intervention to stop an enemy and let Garp go ahead on his way.
- With Roger and Rayleigh absences, show Gaban taking control of the crew and giving them instructions of what to do.
- Show an important clash in the background (Sunbell vs Barbell for example)...
Point is, some of these things probably happened offscreen, but not seeing even a glimpse of them takes away from the experience.
All things that could be solved by adding some good panels here and there chapter by chapter (see Marineford).
Flashback isn't finished, so I'm not dropping the ball yet, but I'm starting to worry...