The actor is irrelevant, the point is that Sauron in Shadow of War matches all the societal criteria of male beauty, including brushed hair and clean-shaved face.
That's why Halbrand logically doesn't work as Sauron. Outliers and contrarians always exist, but typically the common folk isn't attracted to a guy with messy hair and unkempt stubble.
Anyone who wishes to play Annatar should at least check those things first.