1 minute ago, Woorloog said:It is not. The BTL-B may have the same overall layout but the turret is especially different in the BTL-A4. Not to mention the model designation, which kinda implies there are other differences (ie its quite different craft inside, even ignoring external differences). The original cross-sections book had a pick of the OT-era Y-wing with plating and it looks still like the S3/A4 model, just with center section covered up. While perhaps no longer canon, i do think that it might still well represent plated A4 Y-wings.
There is space in the timeline for variety of Y-wing variants. Say A4s were built roughly 5 years after the Clone Wars, they'd be old pieces of junk by the OT-era.
To give a real world example, toward the end of the Second World War the British built two light fleet carrier classes, Colossus and Majestic. The primary difference was the internal electrical systems, but they were defined as separate classes. My point being that just because there is a different letter on the end it doesn’t necessarily mean there is a major visible structural difference.
That said, I’m all for variants. I love y-wings
I just don’t think that there is scope to make a bigger medium base version because just upscaling a fighter is stupid.