it's every team that plays Barcelona plays a 10 - 1 formation; that's 10 defenders and 1 forward. period. it's never barcelona doing that to chelsea or manchester united.
to be fair to every team involved, barcelona playing a "10-1" (what manchester united and chelsea have been playing hasn't been close to a 10-1) wouldn't go over so well. they wouldn't exactly be playing to their strengths
now getting the result is obviously important, but united and chelsea had no choice but to play a 10 -1. other wise, they'd probably get slaughtered.
i don't know about slaughtered, but that would play directly into the hands of barcelona
it's unrealistic that a team could break down a "packed box" strategy. let's be real here.
look, barcelona has seen the same thing for 360 minutes and hasn't made an adjustment. it's all part of the game. it's certainly not unrealistic. the game is played 11 v 11, w/one ball, and two goals. beyond that, it's whoever scores more, and naturally, the best team would be the one who scores more consistently