I personally don't believe the Theban Sacred Band was made of homosexual lovers. If gay lovers were such great warriors, wouldn't every city-state create a band of such soldiers? I think it was a gimmick for their dense formations. "They're so close, like lovers" sorta thing.

The Praetorian Guards don't really have alot of campaigning or battles to rely on. The only battle that the Praetorian Guards participated in (off the top of my head) was Milvian Bridge.