Where I maybe part company with you is in the use of the term "collusive." "Collusive" has a connotation of devious or underhanded which "cooperative" does not. I see collusion on the mat as always a problem.
It's particularly a problem because it's so easy for cooperation to shade into collusion. If we're all working on something subtle, and I'm giving good, sensitive feedback as uke--where's the line between responding sensitively and amplifying what my partner is doing to the point where my feedback is bogus? Or if I'm working with a junior who just isn't getting it and so I start moving in the right direction so he'll at least get the feeling for where he's trying to move me, have I colluded in giving him a false sense of success? Or if we're working with punches, are we colluding in fooling each other because we don't set up a combination and connect with the second punch if our partner hasn't dealt with the first is a way that prevents it?
This is the issue with training. It takes ongoing vigilance to make sure that we haven't drifted off to happy fantasy land.
I would suggest that we do not really disagree. The process of developing a collusive relationship does represent positive aspects about people's ability to connected, cooperate and communicate at a pre-conscious/non-verbal level. I agree that this process is destructive to a more realistic training style, if is it not constantly watched for and actively/consciously addressed.