This could fit in if you simply figure that Franky doesn't join the crew. But whether it can fit or not, not too many people care. Actually, it'd be a little disappointing if any had the possibility of happening, because non-Oda plots generally suck tons of kangaroo ass.
@Malintex_Terek:
Think of the OP Movies as the equivalent of a Gantz game. The Strawhats are out adventuring when they are suddenly abudcted by Gantz who tells them their lives are over (that's the theory, anyway) and they're forced into a scenario they have to complete. At the end of the scenario (movie), the Strawhats points (box office gross) are totalled and they're sent back into the real world.
Perfect sense, really. It's just like plucking the Strawhats out of where they are in the manga and plopping them down in another timeline.
…..? Well, I won't lie, that was certainly original.