I'm glad to see that even if I couldn't tell exactly what the issue was it looks like my eye is at least finding the area. That is a huge step for just over a year working on it. Thank you for taking the time to go over him.Bear in mind Dictator was a 10 year old dog in this video. Most 10 year old males would show some thickening of the neck. But he has good length of neck.
I don't think he's so short on shoulder angulation but rather shows to some degree a fault that was very common then and for a good many years after that--his front sits a little foreward of where it probably should--the end result is that he is a little bench fronted. The angulation itself looks pretty good.
His tail set looks a little low to me--but that may be because I think he's a bit rounder in the croup than he should be. I think almost every stacked picture of him has the hind leg that is toward the camera stretched out to flatten his croup a little.
And he's definitely a compact dog.
But all things considered--if you look at pictures of Dobermans from his period--he is overall much better than most and it certainly looks like he could move.