The figure of 10,000 is not one that pepe has pulled out of thin air. This figure is important to the Taliban for some reason, they think that once the momin mujahids crack jobs reach the number of 10,000 and march together they are invincible.
Not that they would have any chance against the Pak army or even any other armed group…
No one thinks that they will take over any major cities immediately. Changes in behavior brought about by threats or by the population volunteering them for perceived security are altering the socio-cultural fabric pushing it further to the right.