How to plan contract manufacturing sell-buy components

Summary:

Hi,

I have been looking at supplier chain collaboration and contract manufacturing for planning below scenario but still I am not sure if that meets my requirements and if is really needed SCC and CM setup.

We are buying components (PCB) to a supplier A. PCB's are directly shipped from supplier A to another supplier B who is doing assembly.

We have demand (Forecast) for FG item.

PCB is the main component in the BOM for FG item.

We are selling the PCB's to Supplier B and then buying the FG item from supplier B. That is the tricky part I am stuck.