Correct me if I'm wrong, but isn't this idea already working?
The example mission clearly demonstrates that AI are capable of utilising the gate, (even if it does take them a few attempts to navigate the stairs) and it wouldn't be too complicated to set the script to synchronise to a trigger.
Reinforcements could be simply a case of detecting if there are below a certain number of Gould in an area, and if so, sending the next group through the gate.
I'm not that proficient yet with ArmA scripting to comment upon random travelling, but I can see it being possible. A slightly easier solution would be for mission makers to simply introduce a higher level of gate traffic.
Eg.
Gould squad patrols gate 1 area.
Gould squad moves through gate 1 to gate 2.
Gould squad patrols gate 2 area.
gould squad moves through gate 2 to gate 3.
Gould squad patrols gate 3 area.
Gould squad moves through gate 3 to gate 1.
Rinse and repeat.
Have a couple of squads following that pattern, and you've soon got traffic, that whilst not random, is difficult to keep track of.
