Keith, as an example of what I am talking about, I would refer you to this YouTube presentation in which Sensei Gozo Shioda, the founder of Yoshinkan Aikido, is giving a demonstration.
Shioda liked to illustrate the principle I am talking about by having his uke rush toward him fast and try to shove him hard in the chest. Just at the moment the uke's hands are about to make contact with his chest, Sensei Shido moves his entire being forward less than one inch, almost imperceptibly. The results are quite marked.
The attacker is covering distance, has momentum; Shioda Sensei seems to hardly move. Yet what is the result? The uke is thrown violently to the floor.
I simply did this to an opponent who was bent over, head down, trying to wrap up my knees.
If done with proper timing, *(Heck, EVERY AIKIDO TECH. HAS TO BE DONE WITH PROPER TIMING) the results speak for themselves.
Get the timing wrong, go to early, go too late, don't go strong enough, etc. of course it won't work.
But I've gotten that one right several times, so it's just not a nice theory that I have.