I find your thoughts really interesting noyd because I wondered how somebody who wasn't overly aware of Goldberg would view that documentary.
It basically confirmed what I thought it would.
I'll put it to you like this, when Goldberg hit the scene, he was a rookie inside the first year of his training with very little background outside of the Power Plant. However, he picked up on things - intensity, pose, charisma - that usually takes wrestlers years to learn and even then, they normally don't get it.
He also wasn't your typical hoss either. Goldberg was clearly into MMA and was one of the first to employ their brand of action into the wrestling ring.
The problem was, at some point, the other main event talent got into his ear, told him to slow it down, so he did so he became known as the spear/jackhammer guy.
But as evidenced by matches against DDP & Steiner - he was capable of a lot more.
So yeah, the documentary never really put the point of him being a ridiculously fast learner across. Or how the locker room basically corrupted him and taught him that he didn't have to try.
Sadly instead of showing he had potential they had to put across the Regal match which to be honest, would be like dedicating a segment of Cena's rise to some match he had against Dupree. Like, maybe a few people talk about it, it's a DVD extra at best but when trying to tell his story - it isn't a priority.