It's all seat time Doc. I recently left the trucking industry both as an owner and a driver for the last 35 years. I am good with trucks and wheel loaders, but had only done stuff like randomly loading trucks with an excavator through those years.
Now I have a job in a mine and besides the loader I now have to operate the excavator and D6T dozer. I'm lucky that with my job, no one is there pressuring me. It is pretty easy going. So after a few days it is surprising how naturally your hand movements will come to you.
Last time I ever had to run shovel, I was put on a pipeline job with guys in the hole. I HATED that and went back trucking. Now that I have no pressure, I am actually getting way better on it.
Only problem I have now is getting out of the Cat and trying to reverse my hands to run my new Kubota backhoe, LOL