I just look at those results on the TR review.
The
hardware.fr article also has similar results. In this and their previous article GM107 is consistent with 1/3 rate while GM204 is somewhat
overperforming a 1/3 rate on culled tri's. It is, however, closer 1/3 rate than 1/2 rate and I can only attribute the performance to GM204 hitting some rather large boost clock on what it possibly a relatively low power scenario; GM200 probably isn't hitting similar boost levels hence looks like it underperforming relative to it number of SMM's in comparison to GM204.