Great description!
We read a lot about lather problems on SRP.
But what we all don't tell is............is that everyday can be a good lather day or a bad lather day for anyone. It's just that those that have been doing this for a while recognize when they need more soap or more water, and then added it as need with each shave.
It is the ability to recognize which one you need for each shave is what you need to learn. That's s why learning one soap show will you what consistence the lather should be, then it's reproducible with each soap you try out.