It is very unfortunate that, to train in a formal way we have to go through repeated techniques of one type, whereas ideally we want to be changing our technique every time to respond to that particular uke and that attack. How do we simulate this? Possibly a lot of it is attitude? Possibly just later on we have to develop the fluidity.
One thing that my teacher advocates for yudansha at our dojo is for them to do the same technique four different ways each time it's their turn to take the role of nage. Rather than just sticking to a single manner of doing a certain technique, he allows them to do subtle variations should they wish.
Also, I've never seen him comment if a "different" technique comes out of a certain attack. He even commented during his last seminar that it's preferable for a "different" technique to happen rather than freezing or giving up...