“Shimon Hatzadik met with Alexander”
There is no non-Jewish source for such a meeting. But that doesn’t mean it didn’t happen. We were a pretty insignificant people in the eyes of the Greeks and Persians.
Alexander is treated pretty favorably by Chazal given that he was an idol worshiper. Surprisingly they do not comment on his personal life, which, er, uh, wasn’t exactly how a good Ben Noach should have lived.