GSX, by definition, it's based on the concept of tasks so, vehicles and people are usually supposed to be animated, doing something. There are additional people that do less important task, which are more or less static, like the vehicle drivers, but they are in the vehicles.
For example, the tow truck vehicle will have a driver inside, and a wingwalker, of course the wingwalker does most of the job and it's fully animated, the driver is there just for completeness, but there you already have two people for a vehicle.
Same for the catering vehicle, there's a character that does the loading/unloading of carts from the airplane, which is fully animated, and the driver.
When you announce your intentions to park at a specific spot, the parking will be prepared with all the needed vehicles, which means two people on the two truck, two on the baggage loader (loader and driver), a driver for the staircase and perhaps a marshaller if there's no docking system, so it's at least 6 people visible at the same time, with others coming in sequence, like the catering guys.
We are also thinking about future expansions (meaning, not the first release) to use GSX as an automatic scenery detailer, adding static objects like trucks, baggage carts and even static people on the sceneries, at least on the parkings close to your viewpoint.