I am not exactly sure what you are asking. Each competitor should have same troubleshooting problem, same equipment, same diagrams and same amount of time.
That takes me back to my days of tech school when I was in the Army. The faculty had an inventory of modules with documented faults, and we would be tested for our ability to find the faulty one. We would typically have 10 minutes to isolate the fault, then would tell the proctor which module was the faulty one. It wasn't a competition, but of course we would compare our times for bragging rights We would usually work in teams of two, and all had the same fault to troubleshoot. That scheme would make a good competition, I think.