You will get better humidity reduction if you operate the units a little short on capacity. That is let it run 24/7 rather than cycle on and off. If you have excess cooling capacity, the units will pull your temperature down and will satisfy the sensible cooling demands of the thermostat. Since you have 3 units, shut one off and let the other handle the load, even if it lets the temperature come up a couple of degrees. With the compressors running, the evaporator is cold and will condense the moisture in the RV.
Ken