Report On "Shared" Custom objects

[JAW99]

Have run into an issue here... I have a custom object to track employee activity- call it "Install" (which can have activities).

Sometimes one employee does the instal, sometimes two, maybe even three.

Everyone on the install needs credit for having gone on the install. 

So far I have an owner and a multi-pick field to capture the accompanying employees. 

I can run a report that shows all Installs an employee has been on - OWNS or is in the Accompanying Field - but I can't make one report to show this for all employees.

I could run metrics for the employee group but I run into limitations on the Dashboard.

Any help? Frequency report on the multi-pick would be the working option but it's a fix Salesforce has ignored for years.