If you are referring to additional people animation added by 3d party sceneries, GSX doesn't know anything about their existence, so it's entirely normal they would walk into each other, and there's just nothing GSX can do, since these animations are usually made as "groups", rather than single objects, so it's not even possible to know their precise location when they walk around.
FSDT sceneries that use such animations, have a way to communicate to GSX about the existence of these kind of objects, so GSX is able to remove them from the active parking.
GSX vehicles running in front of each other shouldn't usually happen. They are not really "aware" of each other, because if they did, another whole new class of most complex problems will appear, like traffic deadlocks on the apron. It has been like this since GSX has been released though and can usually fixed by changing their starting positions with the parking customization page.
GSX vehicles running into FSX *default* airport vehicles it's usually best fixed by turning down the Ground Traffic density slider in the FSX setting, and many developers already disabled them by setting the parking type to GA or military.
