The more a technology is used, the more likely it is to be copied.
Look what happened to the B-29. Soviets forced it to land and within 2 years had their own mass produced copy of it. Granted their absolute lack of aerial refueling and forced use of thicker metal in construction meant that it weighed over a ton more and any bombing of the continental US would be a one-way mission, but a mass produced copy nonetheless. The RH have no such impedances.
Lib Dreads: 94
LABCs: 83
Carriers: 26
LSCs: 96
Rheinland Cruiser: 81
Rheinland Turtle: 56
Kusari Battleship: 29
Kusari Destroyer: 57
Bretonia Battleships: 38 (Though these have no fuel, essentially 0)
Bretonia Destroyers: 38 (same as BBB)