Please do not get me wrong here. I am not suggesting that the technique is done poorly, I am assuming that the technique is done correctly. And I think that Katherine also meant to give an example of someone who is doing the technique in itself correct.It is from that starting point that the question on the use of strength comes. Hence my response.
I'm not suggesting you are saying that, but I am saying it. If the person can use their strength to pick you up with one arm when you are doing ikkyo, then there is something wrong with your ikkyo. I'm not very big myself and it has happened to me many times. It was a good learning experience, and improved my ikkyo a lot.