Both tests reaching a locked framerate doesn't mean they matched the performance.It's not the same code indeed, it was a stress test on Scorpio with full lod and complete physics for all cars, something that apparently the full games optmizes.
And the test was: Even a 1070 doesn't match the level of performance they showed on scorpio with this game, only a 1080 matched.
Keep in mind that this particular demo only used about 55-65% of the gpu time according do DF, and Forza 6 on Xbone uses about 90%.
So please, you stop. You are the one trying to infer I'm saying scorpio is a 1080 equivalent as I clearly saying it matched the performance for this test.
Both the Scorpio and a 1080 could run Super Mario Bros. at a locked 60, that doesn't mean they are equal, even if they got equal results in that test.