NNKarma

The only way it might make sense is for picks because the whole idea of the early trade period is to avoid such super teams, also it would be torture for coaches having to plan for ever changing teams.

Even, then, if they really cared they would make the friendly helmet to helmet illegal celebrations, but they probably don't want to put the idea in people's heads that those small hits can also cause damage.

All depends on how you define progress, probably in managing it but not much in preventing. I doubt you would make serious reduction without eliminating the defense or making it flag football.