It's hard to completely blame Pompey for his defeat at Pharsalus. Though he had more numbers, he had mostly new recruits (except for his 1st Legion) countering Caesar's highly experienced Gallic/Spanish legions. His strategy of starving Caesar out was slowly working (just like Fabius Maximus Cunctator had done to Hannibal) but was forced to give battle by the various senators in his camp (was essentially a hired gun... not truly in command). If I had to think of an overrated general, Mark Anthony comes to mind... his campaign against the Parthians (I believe it was them) was an inept disaster!