BV, SOX80 and Dominator2,
I think that formation take offs (and landings) were just the way we did it in my day, and they were a tactical solution to a Cold War problem, that of getting missions off the ground as quickly as damm possible and away into a tactical 2 ship, 4 ship, 6 ship or 8 ship formation heading for a pre destined tactical attack target on Day 1 hour 1. Strike was rather different and at least the QRA would have gone off solo and continued that way all the way to the target.
Launching for the wars of 1990 onwards has been rather different, there is not (usually) the same desperate need to get aloft in such a split arse manner, but you still see pairs take offs from Cyprus on the news.