I would strongly suspect that a more straightforward Embassy-BM would beat scout/steward shenanigans. Your opponent did things like buy a Market with $6 instead of a harem or gold - twice! (In the end, the only treasure in his deck was 2 gold, 1 silver, 1 harem, and 7 coppers. He also had 2 markets which would have been better as golds or harems, and 1 hunting party which would probably have been better as a second embassy).