Thinking that this depiction of Cleopatra is a historically accurate depiction of a Greek queen of Egypt
is like thinking that Denzel Washington in The Bards' Play is historically accurate in it's depiction of a King of Scotland.
Or, for that matter, that any of Wm Shakespeare's Plays were anything more than entertaining historical fiction narratives, based on elements of historical facts.
If it is decent acting, one can relate and enjoy the presentation and be entertained, while also holding the idea might not depict historical fact; and as such may come to the understanding that this type of venture can point out the ideals of a free human, their thoughts and actions, are more human elements than the actors ethnicity deliberately chosen by the director.
Live Stage Productions of the play "Julius Caesar" have been put on, where all dialogue from Shakespeare is spoken with accuracy, yet all the actors in the play are dressed in WWII era Nazi Military Uniforms, rather than the standard Toga of the historically accurate timeline garb.
One benefit of artistic license taken by directors and producers, is that such a depiction entices the audience to focus on what is said, rather than what is seen.