Well, as with any formation team, including the Red Arrows, (which I'd LOVE to see btw) not every formation is flown with the same seperations... especially if they're in a "unique" configuration such as landing gear and tailhook extended like in my first picture. Considering the tailhook is a good 5 feet long, and also all the the extra drag from the weels... they've gotta be a bit farther appart. The formation rolls and loops and the "Diamond 360" are flown in the tighter 18 inch wingtip to canopy formation.
Check this picture out from the backseat in the left wingmans spot (#2) and see how close he is at the top of the dirty loop:

And from the Slot (#4)

And here is a shot from the slot position as the formation sets up for another maneuver. And it should be noted, this is in a more "relaxed" formation as they are just setting up... once they get in front of the crowd they'll move it in closer.