Re: Can Strelets/Zvezda Great Northern War figures be painted as WSS?
Actually, Swedish uniforms had some idiosyncracies that would make them less suitable for other nations' armies, although those of Brandenburg-Prussia and Denmark were close enough that you could paint them as Prussians or Danes (both of whose armies served with Marlborough) - though you should avoid the Swedes in the "karups" caps, as those were not seen in Continental armies.
The Strelets Russians are a little more unusual and not well suited for other armies where they wear the peakless "kartuz" cap or the guard grenadiers the Peter the Great set, with their unique feathered caps, or the pikemen. Also, Russians with a sword bayonet in the musket are not relevant for the WSS as Continental armies had mostly replaced sword and plug bayonets with socket ones by 1701 when war broke out. On the other hand, the Strelets artillery sets and most of the cavalry sets for GNW - as well as all six Zvezda ones - are quite useful for WSS, with the minor caveats above. The Swedes are still more appropriate for Danes or Prussians than French, British or Austrians/Imperials, while the Russians are good substitutes for Imperial troops.