We've been rasing with a HJ Kaiser class this deployment. Its doesn't strike me as being monstrous.
The
Kaiser's aren't much larger in length (just over 30m longer than
Berlin), but they are about 50% greater displacement (roughly 30k vs 20k tons). But the
Kaiser's are old and tired and having a lot of mechanical issues, and are due to be replaced by the
John Lewis-class.
The
John Lewis-class displaces almost 2.5x what the
Berlin-class does
. There's not many operational yet, but having seen one in real life it feels noticeably bigger than almost every other AOR I've worked with. This is great to support Carrier Strike Groups, because the CVN is also restricted in where it can go because of its size and force protection requirements. They also have unique USN-specific capabilities like the ability to RAS aviation fuel at almost 10x the rate of most other AORs.
But they're big and expensive, and don't offer you much besides the ability to provide a ton of fuel, ammo, and food/cargo quickly. While this is ideal for CSG ops, and ultimately is the core mandate of an AOR, the Americans I've spoken with are interested in smaller AORs that can provide additional services to a Task Group of destroyers and frigates such as surgical capabilities and enhanced aviation maintenance facilities. You don't need those things if you're near a CVN, but there's lots of naval operations that will occur too far from a CSG for it to be an option.
The US is struggling with both AOR platform and crew availability, and Military Sealift Command is stretched pretty thin sustaining global USN force projection. I don't think you're going to see any major shift in what they're building, but I am confident that they would love if allied "small AORs" like
Berlin/
Protecteur, RFAs, etc. started becoming more readily available because it would let them focus the specialized USNS "big AORs" to their CSGs.