Yeah, that's really not the primary reason that there's a split between Presbyterians and Methodists; for the most part Presbyterians don't have a damned clue what predestination means . . . that's according to a Presbyterian theologian and retired Presbyterian seminary professor. I've gone to Presbyterian churches for the last 30 years and not once has the topic of predestination been raised other than to say "yeah, um, next question . . . ."I do believe there is a split between Presbyterians, who believe in predestination, and Methodist, who believe in free will (for example). The first group does not focus on evangelizing, because of their belief in the elect. The second does because of the Great Commission.
The primary reason for the split was that Presbyterian's required every church's pastor to be college educated, and Methodists didn't* . . . along with Baptists and several Presbyterian offshoots like the Cumberland Presbyterian Church . . . .
*Methodists weren't anti-education, they just thought that getting more preachers into the field faster would likely serve the KoG more than waiting until those same guys could pass classes at Harvard.