ok so you are saying that 6 to 7 thousand vehicles comes out from point A(div cantts) , B, C and and is moving to Point X, lets suppose that is somewhere in rajistan, now i am saying that once these vehicle comes on road in urban areas, some civilian just see and calls to his "relatives" in pak and in code words tell him, now you know that in the past IA has done exercise in that area so one can anticipate a possible zone where x is located, so you activate your humint in the area, there are lot of small settlements dispersed in the desert, once the advance party reaches closer to x, a tipoff is made by humint, now i know its that its not that simple, but when such large convoy move, a lot of things have to be prepared in advance, which also gives indication to your enemy. Also take into account reaction time, what IA will do in 72 hours, PA can do in 48 max because of lesser distance from border.
But the mole thing, that seems too straight forward.
