I made a quick and dirty rule that is using people from Redlands Redevelopment example. The rule is like this
@StartRule
PlacePeople-->
scatter(surface, 50, uniform) {Populate}
Populate-->
i(fileRandom("/Example_Redlands_Redevelopment__2016_0/assets/3D_City_Design_Assets/People_by_lowpolygon3d_com/Person_*.obj"))
r(0,rand(60,320),0)
and result is like below