Fluff, nothing more nothing less.
The SovSoy is fluffed as being awesome, I find it lacking, of course that could be due to the fact that 2 out of 3 of my versions of TRO3057 are missing the full stats for the craft, but even the full stats are, meh. I find that too much space was allocated to cargo with SLDF ships, when on top of the thousands of warships, you have 10,000's of Jumpships, for your merchant fleet. This all goes back to the original ships basically being pulled out of thin air with no construction rules.
However by the time they took the effort to make rounded warships, when TRO3057 was released we were stuck with a couple dozen classes of ships that make no sense, sorta like the dimension's of the ships make no sense, or the armor thickness makes no sense.
Also with SLDF/TH ships, cost was never an issue, they had a couple thousand destroyers and cruiser's, and before the Succession Wars there appears that almost every habitable TH system would have Yard space for Jumpships and Warships, it would have to just to be able to maintain the fleet.