maybe a stupid question

Being a north of the border person who may get to spend 6 solid months in and near Zihua, it occurred to me that in el centro at night, given the plethora of resources, municipal and estal policia, army and navy, that a small portion of this "protection" could be put on foot or motorcycle during the higher crime periods : evenings and weekends? It would seem less expensive and more effective . Maybe that is not the point of the multiple military and police vehicles I observed at 6:00pm on 12/7 between la ropa and el centro? I suspect the "bad guys" are able to text each other ahead of time as the check points are being set up.