Filmmaker's arrogance casting the lead (6)
I believe the answer is:
auteur
'lead' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's a link between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for auteur that I've seen before include "Film director whose work has a distinctively personal quality" , "director who's unique" .)