I really think you are discussing about two different things using the same example.
Of course blending happens in lots of martial arts. It fact this is pretty much the essence of every one time counter.
I includes leaving the attack of you opponent largely undisturbed, absorbing his energy.
Of course you can join physically or mentally but the predicate for one time counter is more a mental blending rather than a physical.
This is not especially at aiki trade mark.
You all know the ken awase, which are blending practice.
Look at the first ken awase and look at that
Surely it is very obvious that it produces the same result using the same method.
On the same token, it is true that the last vid focuses on the making it happen and the aiki-ken is much more about the fashion in which you do it/get there. So you can say that there is a world of difference
You can look at it either way and none of them is more right that the other or antinomic.
When you have blade contact the same does apply. The blending aspect is the same
You can see as a technique oriented exercise or focus on the aspect of strength with no strength/fencing with the strength of your body/proper body-mechanic and leverage because when fencing any application of active antagonistic force can be turned against you much more easily than with open hand.
there is no need fro strength