Excellent point, however, the survivability of the platform is an open question. Thos Cleveland hulls were not all that great. In fact, the Clevelands were a very bad design, being top heavy and prone to roll when firing all out, which affected accuracy.
I like your MLRS soultion, but I recall that experience with rocket-launching ships was very bad at Omaha Beach, Okinawa and Iwo Jima. Again, the stability issue loomos large. If someone could knock that problem, it might work. Personally, I'd rather see that solution applied to a brown-water vessel, capable of moving close inshore and up rivers.