A little bit of a ramble here:
Different mental models is kind of a fascinating thing for me. I don't always pick up on something as quickly as my peers when it comes to things like math and pattern recognition, but I've tended to make up for that with a hard work ethic and what I think of as rabid curiosity and a strong desire to constantly grow my work skill set and knowledge. I've grown a lot during my career as a result when colleagues who had much higher GPAs stagnated. It's interesting how wide and varied our brains are. Again, when doing any pattern recognition games (e.g. speed, set...etc) with my wife...I don't think I'm bad, but she is grasping things at a rate of 3-6x what I can and it was the same in any hard STEM classes that we took together. It's the opposite for things like history where she can't pick up as much of what is going on in a lecture or documentary or whatever. Physically speaking I'm not sure how the brain works differently between us, but I'm guessing the weights are just different if it's anything like the NN in computer science. We were playing dominoes the other day and I had to pause to check which had already been played and she got a little frustrated that I was taking too much time - like what do you mean you don't already know which ones have been played? So I guess it's a greater ability to recognize and retain patterns quickly.
In your case of the worker, I wonder if they were just dangerously clueless or just needed a little more time to build that mental model to grasp how the pieces all fit together. I also wonder how I would have faired.
We assembled a plastic product with about 20 components of different shapes and sizes. There were slots to align and friction fit, there were things to click, wires to route, glue to dab etc.
The far extreme of "can think in 3D" were the people who could be shown the finished item, the kit of parts and pretty much just assemble it. They would miss some "trick" or "knack" we had developed and they might not quite get the alignment or placement of a part perfectly but the product would work.
The opposite end were the people who unless I was stood with them and helping to move the components in to alignment just simply couldn't "get" it. It was as if they didn't have a the ability to retain the finished view and movement through 3D space required to complete the movement. Could also have been a coordination, dexterity or proprioception issue.
Of course this was a spectrum and we had to make a judgement call (often in discussion with them) about how they would improve/get up to speed or if it was a lost cause. We built jigs and tools to help remove the finesse required in the assembly which helped a lot BUT, when you got someone who could just see it no amount of training or jigs could get everyone to that speed.
On quiet days we would have little competitions on certain stations to see if people could get a new record and it was those days when you could really see the people who just got it. The best example I can give was making the final cardboard packing boxes, this was an 8 movement process from flat box to assembled with lid open, the record was 2.7 sections, a sustainable pace (so the time that actually mattered) was around 7 seconds, people who just couldn't get it were over 30 seconds and usually with many quality issues as at those people were often fighting the box and material.
(It was a graduate level real analysis course, and people who had been calculus whizzes were struggling with point set topology proofs.)