I wasn't referring to Lupin, I was referring to Flitwick who is an accomplished professor as well as a duelling champion.
Yes, Ginny is above average but not anything over the top, and fighting Flitwick is still tougher than dueling three teenagers, with one being incompetent and only one being "good" compared to other adult duelists.
I know Flitwick defeated Dolohov, but what I was saying is: Bellatrix survived for longer than Dolohov because she had an easier fight. Bellatrix being the last one standing doesn't necessarily mean she's better than Dolohov.
You do realise we're not talking feats, but writer's intent? And yo do realise that these 2 duels weren't the only duels they had in the Battle of Hogwarts?
I've said it twice already, wether or not Flitwick is better than 3 other witches combined is not the point here. Rowling chose to compare Bellatrix to her master for a reason, and that's because she's intented to be better.