I'm trying to manage a project where the schedules of one contractor directly impact those of every other contractor on board but not vice versa.

The smaller contractors need to see any changes made to the schedule of the large contractor but don't need to see each other's schedules.

The preferred method would be that the work packages in the large contractor's project were shared in a read-only style arrangement with the smaller contractors' projects. Schedule changes would be made to a single work package and these changes would be visible in the packages/gantt chart of the smaller contractors.

The alternate method - the logic seems upside down to me - would be to have the large contractor project as a sub-project of multiple smaller contractors projects. 

I've had a look through the forums and found a couple of similar ideas but never a solution to my problem:
https://community.openproject.org/topics/7586

tl;dr: be able to make workpackages visible in sub-projects or sibling-projects, with all attributes linked to the master work package