For Christs sake, the galleys are different. They are from different vendors.
America Wests are a single galley, standard factory or whatever was on the secondhand plane when they got them. They are more similar to our 80's era Boeing galleys. The drawers are bigger (the notorious blue ones get stuck in east full size carts and don't fit on top of them, they bow half size carts to the point where they are unusable.)
US Airways galleys on every plane they've ordered since 1997 are from the same vendor and are interchangable. This includes wholly owned jets. You can pull an Atlas carrier or cart off an A330 and load it onto a PSA CRJ. Someone, probably a whole team experienced in such things, at the Wolf-era US Airways sat down and designed a system with a standard aft galley config for Airbus narrowbodies, and one for the forward that built upon itself on the three narrowbody derivatives, keeping in mind the larger number of FC seats from the 319 to the 320 to the 321. A330 galleys used the same equipment and packouts, but obviously on a much larger scale. When the MDA 170s and PSA CRJs were delivered US had them configured to use the same items as the Airbuses, to create an eventual single set fleetwide. It was a very smart move if you ask me, rather than having 16 different types of beverage carts and 8 different size drawers stocked at every catering station for whatever odd bird happens to drop in.
We all know that the way of doing things at the new US is to question the tried-and-true, "major airline" "East" way of doing something, have someone entirely unqualified come up with a cheap and tacky looking new way to do it, set it out untested, have it fail miserably, blame it on something like the weather, then put band-aids on the new way rather than go back to the original thing that worked. It's an immature frat-boy pride mentality that we've seen on everything from reservation systems to trash bags.
The galleys are designed entirely differently, and weird as it sounds the ideas of them are different... The east ones were designed with half-size items to rotate- use a cart or carrier, then pull out its replacement from behind it, with entire carts or carriers replaced. This makes for quicker turnaround times with caterers switching out entire carts/carriers rather than looking at individual Diet Cokes and sugar packets.This obviously works better for the larger scale of widebodies etc. The west idea is more like restock what you need, similar to our old Boeings.
The obvious thing to do would be to replace the much smaller west fleet's galleys with east ones, considering the huge amount of stuff US has aquired for it's fleet, not to mention it's simply a more modern way of doing things. Instead they have declared that they are getting all new stuff that will "fit both"- which means cheapest, will take years and years, and doesn't quite fit either. The new carts are incredibly cheap and are still too wide for the drawers. Maybe they are trying to smash our hands or strain our backs into retirement.
The philosophy seems to be why spend the money on consistency, just stuff things wherever you can find space, even if it's under a customer's seat or in an overhead bin. The new US doesn't view itself as a customer service business or an ongoing standalone entity, and these things prove it... just make it work as cheaply as possible, hell, make it not work, just save money and hope to be bought out.