As one of those cross trainers, it has been wonderful to see how the difference can create harmony not discord, by accepting (enter and blending)with the differences rather than judge them (or people) better or worse.
IMHO, everything except actual combat has rules of engagaement. Yes, I know war is supposed to have them to but somehow its so much harder to apply them and live. Who ever sets the rules and turf will probably benefit from them.
I personally would love to see some body with Aikido training step into the cage and give it a reality check. But, it won't be me.