Would project issues be shared between customers across orgs?

[Mark Ellis]

I have one Service Desk set up that services a Main Client, and a Contractor to that client.
Each are set up as their own Customer Organizations within the project
Main Client Org
Contractor Org

Both Orgs' customers submit requests, but everything is in relation to the Main Client.

I set up the separate organizations so that requests submitted by the Main Client would not be seen by the Contractor.
However, if the Contractor submits, the Main Client should be able to replace the Contractor reporter, with the request remaining shared with the Contractor.

Would the Contractor be able to see that specific request? Would they be able to search and see other requests? I'm not entirely clear after reading documentation on project customer permissions.

Thanks,

Mark