Shoji Nishio and his senior Yudansha were not big....He was rather modest in stature even for a Japanese person. He handled me and everything I could throw at him with ease and I am 6'2" 250.
That was my experience too, with Nishio shihan. It goes for most of the Osensei students I practiced for. Tamura shihan, just to name one, was doing the same, in no need of any pushing or pulling. It is sad that they are passing away. What to do now?
We have to make it a collective quest to develop our own aikido towards that level. It takes some time...