I wouldn't put Jianmin on the same level as Xiuying - being good at dodging isn't really much (hell, Ryo couldn't lay a hand on Shozo either - why not him too?). Plus Ryo is seen throwing Jianmin, so he's not that good. As mentioned, Guixiang taught Jianmin so it's likely Guixiang is stronger than Jianmin, and she is seen actually attacking someone in a non-sparring situation.
Assuming that Ziming is one of the four leaders of the Chi You Men (seems up in the air at the moment), I would guess he has a similar skill level to Lan Di; and being his sister, I'd guess Xiuying is also similar in skill.
Baihu is probably the next level down, about on par with Ryo at that point in the game (I think it's supposed to be an evenly matched battle where Ryo only just edges out the win).
It's implied that Ryo grows a lot as a martial artist thanks to Xiuying - not only directly through the moves she teaches (like the Counter Elbow Assault being used against Dou Niu) but also through learning the Wude and settling his mental state. I would wager that Ryo at the start of Shenmue II is not capable of beating Baihu, or even Rod Stunt, Greg More, and Chunyan. Guixiang is probably at this level too, and Jianmin and Shozo below her.