On Barsine, The movie makes her half Greek in order to make her Greek

I say that because she doesn't behave like she has Persian in her at all, she's used as a voice of Greek Feminism. Historically she was pure Persian.

It's interesting what one website I read says about her.

http://www.pothos.org/content/index.php?page=lovers

Modern English has no proper word to denote the relationship between Barsine and Alexander: she was neither a mistress nor a concubine. Her position was that of a woman of the king, which included special status, prestige and some (political) influence without being the king's wife. That was perfectly acceptable to the conquered Persians.