Here's some help: I think most all of them are actual historic classes, you can look at
navalhistory.flixco for more detail.
The Marksman-class is the one exception, that class I can't find a corresponding British destroyer type for.
The Yarrow S type could be seven DDs of the Admiralty S type built at Yarrow (though I don't know that that's the historic number built there). Same with the Thornycroft S, and the Admiralty S might well be the rest of the class (they certainly look the same). The Admiralty V looks like a historic Admiralty V type DD, so the Thornycroft V could well just be Vs built by Thornycroft. The Yarrow M's could be either M or repeat M's built at Yarrow, though it looks like they've been lumped in with some of the other M-class boats since Yarrow only built 6 Ms in total. The R's would probably be the Admiralty Rs and modified Rs, with the Thornycroft Rs being the Thornycroft R specials.