Yep since when those guys know their own shit? There are facts and feats. They never care about that. And I explained why this twit is a pure non sense. They just say the thing they think is cool when they want, depending of their mood.
Lei shen and azshara can be killed by a dagger in the back. Saying on a 1v1 one will lose with certitude is pointless.
Still lei shen is a trained fighter with a lot of battles behind him, while azshara is not. Both the lich king and lei shen have a great avantage against her. Against each others not really.
And for the second part of your comment the Lich king OS all the "greatest champions of azeroth" when he had enought of the fight and was assured they were worthy to serve him.