Ah. If I'm reading this right, you're saying aiki could just be skipped. And yeah, it could. I've trained folks without it at times, and it loses a level of efficiency of movement and a set of options for recovery. Those aren't strictly necessary, but they are useful. If I was sticking to what was strictly necessary, I'd have to be prescient. Aiki training is really about developing options - I think that's most of the point of most training.If you look at MMA and specifically BJJ you can see this principle in effect. There is a lot of nuances needed in BJJ that you can quite simply not really bother with. The 50 guard passes is in reference to that.