Add to that knowing your local market.
If everyone is equipped and more skilled, they will likely have lower costs to provide the same service. An example: let's say you have a financed 48" walkbehind and a 4 acre job asks you for a bid. Your time to do that job will be drastically different than a guy with a paid for, fully booked 72" rider.
It's fine to have your target hourly, but if you are over or underpriced for your market (and your true costs), you'll either run in circles or sit home all day.
Btw..any laborer that you add should always be separate billed man hours.