Is there a way to assign two individuals as one participant on a workflow?

We have investor templates where the investor needs to complete forms and sign (Participant 1).  I would then like to assign one or more people to be Participant 2 and complete some additional forms and countersign the package.  When sending a document for signature from the library can I add multiple users and drag them all as Participant 2?  I assume that the workflow is complete if anyone completes the form as Participant 2, correct?