I created a lot of submarines as Germany to try to bring british industry to a halt by cutting off the supply. How to organize submarine fleets for best interception percentage? What are the tradeoffs?
Group size? For subby hit-and-run smaller fleets (1-3) sounds better but one can hardly afford a leader to all of them, let alone one with a spotter or sub-master skill. Also, I imagine too large a fleet would not be optimal either.
Distribution? When to use any such "properly sized" fleets in 1 specific region vs have larger overlapping areas for each sub fleet?
Unfortunately the game seems to lack any strategic "spreadsheet" or diagrams to measure trade interdiction progress.