We had a situation arise last night I just wanted verification on. There was a Leadership String that was controlled by an A rank. However, this String branched out at one intersection controlled by an opposing player's C leader. Does the A control both branches of a String? I think the answer is yes, but it's not quite clear if Strings can branch off of an opposing player's control disk.
I'm positive that all branches that are connected together are part of the same "area" and so, for leader scoring, the highest-ranked leader will win the entirety of the area, including any and all branches.
Edit: for clarity, I think the only tile that cuts a string is the weft (?) tile - I forget if it's warp or weft but the one that cuts strings is the only one that would make a branch be considered a separate area for scoring purposes.