From the several eagles documentaries out there I got the impression Frey was overbearing. What is not in question is Frey was a raging leftist. It supposedly caused friction when the other bandmates didn’t want to be as political as Frey.
Frey got rid of Don Felder because Felder wasn't sufficiently reverential towards Sen. Alan Cranston (D) when they played at a fundraiser for that loser.