Personally, I can find the lessons best in the judo space than I can find way out there in aikido land. More physical sensation to learn from, I think. Best for this dumb guy.
I do have a question, though ... and not trying to be insulting. What is the benefit of learning how "not to be moved?"
This seems tacky/insulting to say, but "Best way block punch, you no be there." Right? It's always seemed best to me. I know there are certain jutsu branches out there that seem to specialize in "hit me and you can't hurt me" but that smacks of the arms race between armor-piercing vs. armor with armor-piercing always coming out on top.
If they miss, they miss.
OK, back to thread.
Learning "not to be moved" and "not moving" are two very different things.
The first is about stability, the second is about just standing in the way.
It seems to me that it's a no brainer that you'd want to have as much stability as you can when pushed or pulled in a martial situation. That doesn't mean that you can't move - can't go with a push or pull if you choose
to do so - but even then you have to maintain your internal stability, or you're toast.
Is it really that difficult to understand?