Agree on the KM part but not the RM part. As you can see, RM plays opposite to KM and it was similar to MN. The only drawbacks is their caliber (SD ship 16") and low HE damage (Increasing AP damage). If you notice RM shoots at low angle that probably hits on belt armor rather than deck armor. Not all nations does not had a chances to hit belt armor. RM focusing on BB aggressive firepower than CV and SS.