starting in 1613 (Marriage of Elizabeth to Frederick V) the British Crown has been very close to union with all Kinds of German states, so how could the British Crown pick up the Maximum number of German states to be in crown Union with?
Do you mean a union of crowns? Or a personal union, such as that between Hanover and Great Britain in the 18C ?
the latter, I was looking for the Maximum number of German States having the same ruler as the UK/BG/England-Scotland-Ireland
The problem with is salic law, though. To have a German house inherit the British throne AND inherit also the German lands of the previous royal house, the dynasty of the previous royal house would have to have died out, more or less, or at least that particular line of it...
Do it the other way round. German ruler (make him one of those damn Wettins, they always rule about a dozen statelets apiece- Hamlin had a plague of rats, the rest of Germany wasn't so lucky, they got a plague of Wettins) marries a British princess. Then by a succession of childless marriages, early deaths etc etc, that princess, or her descendent, becomes heir/ess to the British throne. No Salic Law in Britain.