Hi Wendy,
We have the ProofHQ standalone and are in the process of setting up WF so have not determined how the integration of platforms will work. If you are using the PHQ standalone, here is how we add teams to proofs:
1. Create a Group with all required users and determine their proofing roles & email notifications (if they need to be different than their personal defaults).
2. We copy the proof and select the appropriate workflow which has the specific group on it by default. (our processes do not allow for the use of stages)
If you prefer not to copy the proof, you could just share the proof with the Group when needed, set the deadline, etc.
Hope this helps, Ondina