"If the EP ended slavery the 13th would not have been necessary would it?"
IMHO...the 13th Amendment just solidified and codified what Lincoln started with the E.P.
If Lincoln wasn't the driving force behind the E.P. and eventually the 13th Amendment...then who was?
Lincoln can take credit for the EP, but it's like claiming a John F'n Kerry won the Vietnam War. The EP was not a measure designed to free slaves out of compassion. It was intended to cause massive slave revolts whereupon the slaves murdered their masters. As a reward, Liincoln intended on repatriating any and all blacks out of the country.
Lincoln's 13th Amendment guaranteed slavery forever.