Can you file a continuation and New employment at the same time?

[positivew]

I have a group of musicians that i am filing "Continuation of previously approved employment without change with the same employer" for a P-1 visa.

I need to also file a "New Employment" P-1S for their road manager.

Can I file for both at the same time, or do I need to wait for the P-1 extension to be approved before filing the P-1S addition?