I understand that you're not being contrary; I think the problem people have with this incident is it was so blatant that both pairs were trying to out-lose each other.
'You are quite right though, enforcing this is going to be very, very difficult. If teams want to proceed down this path then they are indeed going to need to be considerably more subtle. In which case, wouldn't their energy and focus be better spent trying to win 'properly' rather than influence the running order of the knock-out stages? (rhetorical q.)
Yes, what they did was within the rules of Badminton, but it was also in opposition to the Olympic oath that all the athletes pledged to adhere to.