Remember, You can have more than one person clocking into an operation at the same time. So if you have a crew of 2 they can both be clocked into it. This would capture the labor rate for both people.
I would have to do some testing to what that does with the burden in that case. The system is set up for 1 person to run multiple machines, or just run 1 machine at a time (there is a labor=burden setting in the resource group). Basically this setting is for if you have an employee clock into 3 different operations at the same time, is he running 3 machines at once? (you would accrue the actual time for burden, so all 3 operations would have as much burden as his labor. 3 ops for 1 hour = 1 hour labor and 3 hours burden, one for each op) or is he doing them one at at time? (this would be where you set burden = labor, 1 hour labor = 1 hour burden split between the 3 ops).
So if you really want to know how many labor hours are on an operation, if each employee clocks into the operation, it will capture that employees labor at the rate set up by the employee record.