I have one question though, why 6"/53?
The 6in gun is far too heavy and slow to be used as an AA weapon so that only leaves a surface role.
Excellent points. I agree with every one of them. Here's the backstory on the 6"/53:
Right now the standard AA weapon for Texas is the 3"/50. It's considered sufficient for now.
The concept of a dual-purpose battery hasn't quite caught on yet. The 5"/25 was available at this time, but the Naval Staff considers it too heavy for just AA use. And the navy will learn the hard way about the splash issue. The 5"/38 doesn't come into service until 1934, and ships designed for this period will use them in a dual purpose role.
Subsequent refits will trade out 6"/53s on the Rio Grande and replace them with 5"/38s in single mounts. Similar replacements will be made on the Austin Class Battleships, Nueces and Pecos Class Light Cruisers, and the Hallettsville Destroyers. I used to hold on to ships for 30 years, but naval developments have been so fast that I've had to scrap them at 20 years (which evidently, happened to a lot of navies in those days). So you may see extensive refits or new classes altogether if the hull won't take the changes.