You are right to say that the exact dating of Stonehenge is still very uncertain. What is needed is a well dated and reliable stratigraphic sequence for all the phases of the monument and a lot of high quality radiocarbon dates. At the moment we some of this but not enough. The Archer and the Bowmen do not provide a form of proxy dating for Stonehenge but they are important finds in their own right.
You are right to say that