I thought this was really interesting and it made me wonder if the US MAG people have gone into this much detail for their analysis. The only concept that wasn't really touched on, perhaps because it's so obvious, is that all teams are aiming for a moving target because no team is standing still and not trying to improve. It's the "it takes all the running you can do to keep in the same place" idea from Alice in Wonderland. Unfortunately we can't do the experiment of rerunning the triad without US MAG trying something new, but it's very possible that they would have fallen further behind than their recent usual of 4th/5th without the D-score bonus.
One think that irks me about US MAG is the sense of entitlement, the idea that they should be medaling as a team. Just because your WAG team is good, or that you have a large population, doesn't mean that programmes/fans should expect medals. When they kept coming 4th/5th that attitude grated on me.