yeah i was thinking about her being in it too. Xing Cai was about as historically relevant as Xiao Qiao in this case. yet Xiao Qiao was still included in the game and although she didn't have her own story in the game she still was added to major battles. so i don't think historical relevance really mattered in the cutting of characters here since Pang De was one of the ones that got cut too. and last time i checked he was a pretty relevant character too.
The reason she was taken out for reasons of "historical significance" while Xiao Qiao was not? How about that Xing Cai is a fictional character (one of many made up in Romance for dramatic purposes), whereas Xiao Qiao is actually a historical character.