Wouldn't it be kind of dangerous and a tenuous situation for Pompey to ignore Caesar for very long, given how Pompey's army was living off the land in Greece? As almost all ancient armies did when they were on the march, even the well-equipped "mules of Marius" when campaigning for very long and running out of rations. Pompey had to feed his army as much as Caesar did his own, and he would be in a better overall logistical position by opening up supply lines blocked by the enemy in and around Greece, no?