66 more ATM's so that's 33 arrivals, take out the freight movements at night say 5 arrivals that makes 28 more arrivals throughout the day say 0800 to 2200 gives a 14 hour period so that's an average of 2 more arrivals per hour. Hardly a large amount.
Each unit has it's individual complexities be it lack of CAS limited space in the RVA lack of high speed exits, conflicting tracks between SIDs and STARs, and every controller does the best job they can with what they are presented with.