Formations are one of the various topics covered in the party movement mechanic megathread at https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=679414. We can add new thoughts to that if we wish.

I'll lock this other old thread just to prevent a splinter discussion.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"