Change the guy attacking O Sensei from a trained "uke" to say Tenryu the top wrestler or some of the Kodokan judoka he used to play with. Was O Sensei able to deal with these guys using "blending", "leading", etc.? Read the interviews and direct accounts, which describe O Sensei not being moved by active judo guys, or Tenryu feeling as if old Ueshiba's arm was made of iron. What was O Sensei doing to them? Why didn't he just blended, "showed off" waiving his fan, and let them fall by themselves?
I dont understand what part of simple English that people find so difficult to follow.
1) O Sensei did a variety of things in different circumstances.
2) Sensei's ability to ground out significant force was one thing he could do. Tae Chi masters do things like this too.
3) the fact that O Sensei did what you describe some of the time does not mean it was the end all be all Aiki or that what most of us take Aiki to be is wrong.
4) if these guys were trying to stab him he would have done something different.