From a purely outsiders perspective, this seems to be about the standard the National Ballet wants to set.
Using some of the Ballet companies I am familiar with - Royal Ballet, POB, ABT for example - it's difficult to imagine a Swan Lake with the quality of dancers that the National Ballet cast in the performance I saw in June. Perhaps that is unfair because the National Ballet does not have the resources to be compared to those companies period.
The puzzling part for me is that the truly world-class dancers are under utilized. Again, perhaps there are reasons for that.