I thought it was very interesting to hear such a list from someone who's spent so many years telling the historical narrative and interviewing various experts. It was also interesting to see how he limited the list to the years from 476 to 1204.
The list consisted of:
10) Nikephoras II Phokas
9) John I Tzimiskes
8) Romanos Lekapenos
7) Maurice
6) Constantine V (🗿)
5) Heraclius
4) Leo III
3) Alexios Komnenos
2) Basil II
1) Anastasius
I really enjoyed the episode and mostly agree with the list. The only one I don't really agree with being on there is Nikephoros II Phokas- at least as an emperor. He was perhaps the greatest Roman general and conqueror of the post-classical period, but he was not an all-around effective emperor or politician. His successes probably laid the foundation for the successes of Tzimiskes' and Basil's reigns- the conquests of Cilicia and Antioch were major triumphs. But when you're so unpopular with the church and people that no one cares when you're assassinated and replaced by the assassin, you probably were not a very good emperor. I'd have replaced him with John II Komnenos. All around the list was good though