They're supposed to be Fletcher class destroyers, but HT and Pyro subsituted a DE instead. It was in one of Pyro's December news posts just before 1.05 came out, like a week ahead of Christmas or something.
I don't know why, but I assume it has to do with either too much AA or maybe the torpedo launchers.
I know they're too fast, but I don't loose any sleep over it.
Hans.