This is how Mangpai views the chart's controlling work process:
In this chart, there is a strong gang. The gang of Chou, You and You control Xu.
Xu and You do not make a half a season combo. On the contrary You harms Xu to control it.
If you look at Xu and You as a combo, then all the four Branches combine, in which case they don't perform any controlling. If there is no control, then the chart loses out on a big piece of "work".