I think you're half right. If I remember correctly, the last CALALPA pre-merger contract proposal had the 764 in the highest pay band while the was 763 attached to the 762 and 753 in a lower band. The actual CAL pay bands at the time of the merger had all 767s in the highest pay band, while the 747 was banded with the 777 and all 757s and 767s were banded together at UAL.

I agree there was probably posturing by CALALPA in wanting to keep the 764 in the highest band. It had potential SLI implications and was a fleet flown by LCAL pilots and would remain so until after the SLI, so it made sense in looking out for their pilots they would attempt to keep it in the highest pay band. What you neglect to mention is UALALPA attempted to do the exact same thing with the 744, breaking it into its own, new, top paying rate, despite the fact it was banded to the 777 at the time of the merger.

Long story short, both sides did a lot of maneuvering that got us to where we are now and none of it matters anymore... except... we're hiring a lot of pilots who don't carry any legacy baggage and shouldn't be filled up with revisionist history.