Customer Service seems to be a function of the number of destinations you fly to (total routes) and how often you fly to them (flights/week). Which makes sense as every destination is going to have counters that need to be manned. So if you're flying to a lot of destinations with relatively few aircraft, you can very easily have many more CS employees than operational ones. Chances are you have a lot of Ground Service as well for the same reason.
I'm guessing with so many pilots and so few crew, you fly a lot of little puddle jumper flights all over and/or to a few destinations a lot of times per day.