I have two people who are classed as supervisors and dictate what gets done by the others etc, they are also the ones who collect the money in and price up new work. They are on a slightly higher rate for this.
However, we are also looking to changing our whole system and paying everyone a basic wage each week, probably around 85%-90% of what they are averaging now, then at the end of every period, either 4, 8 or 12 weeks (yet to be decided) we pay them a bonus based on that periods work.
The main advantage to this is that if we have a wet week, like recently, then they will still get a regular wage coming in and at the end of the period they should also have a decent bonus as well.