Got'cha, the story is not the issue. Do you continue to have concerns with the storytelling (or have you identified another culprit?) and are you able to elaborate?
To help you diagnose the issue in the process, check out this 'making of' series:
The Making of Cloud Country (a children's book by Pixar Animation Studios artist, Noah Klocek.)
Part 1: https://www.youtube.com/watch?v=BQrUBrzOKfI
Part 2: https://www.youtube.com/watch?v=eZJ-l2KsP_k
Part 3: https://www.youtube.com/watch?v=2qmTdPXcJcI
Maybe this panel talk can help as well:
Lightbox Expo: Art of Storytelling Panel
You shouldn't feel your process is 'amateurism'. I don't think there's any successful project that has ever stuck to the original plan. It's maturing organically
As for your thumbnails, here are one person's thoughts…
- I think the 1st is a nice establishing shot.
- For scene 2, is there a reason why the viewer is placed so distant from the characters? We want to see kitties Can the image be cropped or are we meant to see something in the backyard and alleyway? Are the cat’s tails suppose to be linked?
- Since this is a book format, have you considered putting scenes 3 and 4 onto one page? When separate, it was difficult to make the correlation between the two actions. But, if you plan to add narration then that’ll resolve it.
- Scene 5 looks too rough, but I want to say it could benefit from having more suspense It's interesting how the objects crowd and are angled towards the girls, creating tension. Is that your intent?
Hope this helps.