I could also be wrong, but I don't think that the animated visitors and staff are actual assets. I read somewhere that they are just cosmetic animations that "appear" in greater quantities near higher value exhibits. So I'm not sure the game differentiates visitors from staff.
For example, you don't see people arrive through the monorail and helicopter entrances with the vehicles - they just sort of appear.
Based on the fact that each visitor is not an individual entity with needs, ect. - I don't think this is possible...
Good idea though!