Good one, at that. Though, technically, no. Flank is to attack an enemy from the side. If you flank a flanker, you’re just flanking from a different direction. If a flanker kills you from the right, somebody can flank the flanker from, saw, the left instead of head-on. The directions kinda looks liek a Scrabble board, I’d say. Or maybe a staircase.
Moral of the story, don’t flank a flanking flanker at risk of being flanked, possibly by a flanker or a flanking flanker.
Or gank, who knows.