Yin (for Shang): Feminine, passive, darkness, coldness, earth, fall, valley, west
Yang (for Mulan): Active, masculine, warm, dynamicity, sky, light, spring, mountain, east

I'm sorry if you don't understand the question..

I see Mulan as having a somewhat more passive personality, and she reminds me more of Earth. Shang is more of a spring guy to me, and I see him as being more active.

I think the sequel tried to show them as being a lot more different than they actually are and that the yin and yang could represent either of them. I just feel this fits more logically because, well, idk, the active and masculine jumped out at me. It's probably a subtle pun on Disney's part due to her dressing as a man, though I doubt they looked that far into it.

Feminine for Shang?! hahahahah

If you watch closely, Fa Zhou had the Yin piece, while his wife Fa Li had the Yang. In other words, the Men (Zhou and Shang) have the Yin, while the Women (Li and Mulan) have the Yang.