They don't even need to watch an expert. They can
watch a regular player like me (ok I guess I'm slightly above average, but by no means a LobosJr no-heal SL1 no upgrade yadda yadda kind of expert) do really well against him and only making a few sloppy mistakes.
If I can consistently beat a boss with tons of HP by using only 4 Estus top, then it's an easy boss for sure. I died more to Midir than to Pontiff Sulyvahn or even Nameless King, but now that I finally got his pattern down, I can kick his ass
consistently, which I still can't do with harder bosses like Nameless King, the Princes, etc.