From Wikipedia, which I'd trust at least approximately for the basic numbers, AS+VX have a fleet of 217 (737s and A320 series) plus 78 Q400s and E175s operated by Horizon and Skywest (about 40,093 seats total -- uncertainty because I don't know how the different configurations of 739s are distributed at the moment). B6 has 233 A320s, A321s, and E190s (32,337-35,660 total seats depending on how many of each configuration).

In 2016, AS had 32.8 billion RPMs (excluding Horizon/Skywest), VX 12.1 billion (44.9 billion between the two), and B6 45.6 billion (source: BTS).

You can look up their revenue from their quarterly investor statements.

I'm a little surprised at how comparable they are.