As far as I know, all frames from the same generation are the same, whatever the brand and made by Pacific Cycles.

R&M receives the frames and assemble the bikes with a different choice of components than Pacific Cycles. R&M also discontinued the Birdy World models.

For Bianchi, just a guess, but I think they are also assembled by Pacific Cycles because its only sold in Asia ??

The only frame which is really very different is the titanium Birdy designed, made and sold only by Pacific Cycles (there were 3 generations).

But there were several generation of frames.

I do not know to what generation the Bianchi belongs but its transmission is very different, its a 8s Sram PG-850 11-30T.