Kagome relies on purifying arrows during fights with demons. Sango is no demon, so I assume that there will be no spiritual effect on her if they were to fight.
Quote:
"Kagome is emotionally stronger"
I say different. Sango loses her whole family, and she's still able to smile. Inuyasha says a rude remark, Kagome sits him, goes home and sulks there. Strong? I think not.