I have to agree with you in principal, but also disagree with you. Honestly, the Disney worlds we got were so good that I didn't feel like I needed more Disney. In fact, I could have done without 100 Acre Wood at all. (I do think the Frozen world should have been rewritten altogether, but that one has so much potential that I'd leave it in.) But even with those two, the Disney worlds were still by far the best thing we got in this game.
With that being said, I am going to say this: I wish we had had another original world in this game. I honestly could've done without
100 Acre Wood, the Final World (although I really liked it), playing as Aqua in LOD, and playing as Riku in ROD,
IF it meant we got another full-scale world. Personally, I would've liked to see that world be Hollow Bastion/Radiant Garden. I would have put this world after all of the Disney worlds but before the big endgame.
Why this world? For one, it would put some FF characters in the game--which is the biggest complaint I'm seeing from people. Perhaps we could assist the HBRC with resolving the Cloud vs Sephiroth fight as our "final test" for what's to come. For two, it would give Aqua and Ventus some time to "catch up" in a world they are familiar with (perhaps they could be party members). For three, at the end of this world
Vexen and Demyx could help us use replicas to bring back Roxas, Xion and Namine a little bit sooner than they were in the game, at which point we would have everyone on Team Light except Terra. This would give the Days trio a little more time to catch up as well.
I think this would break up the endgame a little bit better, and also make the game not seem so...suddenly over? I won't lie, I was a little shocked at how abruptly the game ended, and honestly did feel like I could have used another world...just not necessarily a Disney world.