Would it be four leading if one side was reversed (can't quite picture it in my mind). Neat anyway, and problably stopped quite well once or twice.
Me thinks not (I had to get my head around this too....)
Here's a pic of a Suzuki twin-leading-shoe backplate from a T250/350 or similar (LHS of bike), so guess it fair to assume the set up would be 'same' on the LHS of the GT750.
Wheel rotation would be clockwise.
As each shoe acts iindependently, the set up (with clockwise wheel rotation) would have two shoes each with a leading edge.
Reversing would be the same as changing the wheel rotation to anti-clockwise, which would mean the previously leading edges now become trailing edges.
(I think.....