This sounds very interesting, but I also hope it will be balanced correctly if this makes it into the final version. T8-10 are basically clones of the USN ships, meaning great guns to fight enemy destroyers. If the torpedoes are as stealthy as you make it sound like, it seems they are a lot better than IJN torps. I.e these ships might be a lot better gunboats and torpedo boats at the same time (which is already the case with in many situations with Fletcher and Gearing) making IJN DD's completely obsolete. Not being able to hit destroyers with the torpedoes is already compensated by having great guns.
It will be really interesting to see how it works out, but I just hope there won't be too much of a powercreep.
(Note on my low battlecount: I'm an NA player)