Also I am thinking if the theory above is somehow true, but partly and by other happenings. What if:
1. Lady Lan's lover was from WuFeng. Therefore he posed a threat towards her family.
2. The Lan's family knew he is from WuFeng, and in order to separate them and make sure Lady Lan is safe, they sent her to the Gong's to get married.
3.1 That lover found out about Lady Lan being forced to marry another and hence attacked her residence/father.
OR
3.2 WuFeng on its own attacked her family and enslaved them to become spies.
4. WuJi was sent to infiltrate the Gong's and get info, but met Lady Lan and disappeared from WuFeng's map/control if you will.
I know that it was said the previous SW sent people to get WuJi, but don't you all find it a little weird given we all saw how A'Yun and SGQ behaved when they met ZY and SJ respectively? It all seems planned, at least for me.