Exactly. They are nameless. Given how even groups/races on the brink of extinction can pull a billion nameless mooks out of their ass if Blizzard's laziness demands it, it's nothing solid to base their numbers on. Plenty of unnamed Dark Rangers already in WotLK.
This original thought also seems to be not related to the Dark Rangers. What you're talking about now is Sylvanas' potential goals for the Val'kyr she doesn't have yet. Which OK, is a fair point to argue given how she rests the survival of her race (which is in even bigger jeopardy now since Blizzard's writers don't deserve a dime for their "work") on them. But that's something else than the initial post that actually resulted from this though, which was an implication that already existing Dark Rangers are a result of such a ritual (with later mention of how she could have used her aid in Ghostlands as an opportunity for procuring "fuel").