RealZeroAfter I watched all four "An American Tail" movies now, I'm gonna give my take on the while "3 retcons 2" thing and how I'll work with it. This will obviously contain light spoilers for movies 2 - 4 and of course it's just silly fan discussion, I know this is not the canon intended way, I'm just having fun with theories that others have done 25 years ago after all movies were already out. 😁
So, AAT2 is the only one with an age discrepancy between Fievel and Tanya, but only if you take the official statements.
I personally think all four movies can kinda work, if you consider AAT 2 to play AFTER AAT4.
Sure, Fievel says that he dreamed he was in the Wild West and all, but this does not necessarily mean AAT2. I'm sure he dreamed to be a gunslinger more than once!
This, of course, leaves why Tanya is suddenly older in AAT2.
My idea?
Just say she isn't!
AAT4 already showed that she had a childish crush on an adult. AAT3 and 4 state she considers her live boring and wants adventures, as well.
A child wanting to be a Saloon singer is equally as "age inappropriate" but yet as much of a possible dream as her crush on an adult in AAT4.
It's some playful, childish idea that just happens to work out for a while because I guess cats don't care about mice's age!
This leaves only
one thing: Tony flirting with the girl in AAT3 and Bridget being absent in AAT3 and AAT4.
I personally am fine to just take it as Bridget with busy with a job on her own, even Tony got two, and, well, he's just a flirty teenager who, for a moment of having a crush, was crushing a bit on a second girl. Nothing really happens in the end, so, yeah.
So, yeah, putting all that together, my personal headcanon could be:
Timeline is: AAT1, AAT3, AAT4, AAT2
Fievel's and Tanya's age stays consistent between the movies, which would make her quite too young to work/dance in a Saloon, but it's only a temporary thing until the end of the movie.
Tony and Bridget are together / romantically involved.
I can't remember the beginning of AAT2 right now. Considering they had an anti-cat wall in AAT4, I'm not sure if it's likely they'd leave Manhattan at all...but I guess it could work some way.
Like...there are ways in through the wall. Cat R. Waul could've managed that somehow.
But I admit this might be the biggest problem.
I gotta watch the beginning of AAT2 again to think about this a bit more.
Also: I generally think Bridget and Tanya should do more stuff together!
Have them be together for, I don't know, fight for more rights movements together in "We Can Do It!" style clothes and such, I don't know.