Staggered is the HOG style, don't mind this on the open road but in traffic I like to use the whole road at will and not have to worry about cutting another rider off etc.
a good riding formation is like poetry in motion...staggered on straights and in line through corners....great to see...even better when you are part of it...
In a group ride I tend to keep to whatever track I'm on...Inside, outside or centre....and indicate with indicators or by hand when altering course.....
But most importantly I keep a check of everything going on around me, front back or side.....
Bt
Formation.........just me and the white lines
To the left when suffinks cumin
On the white line when on me lonesome.........'cause of animals