Although their rivalry with the 49ers is one of the best in football history, it isn't hard to imagine fan loyalty isn't a strong suit.
Actually the Cleveland Rams were an NFL team, and a good one at that. The Browns were the powerhouse of the All American Conference, displaced the Rams. The Rams decamped for LA and left Cleveland to the Browns, who promptly won the NFL in their first year.
The Browns, not the Rams were in the AAFC. The Cleveland Rams won the NFL championship in 1945 before heading west, NOT because the AAFC Browns were just getting started. The Rams were in the NFL in the ‘30s, before there was a AAFC. Long live Waterfield/Van Brocklin/Crazy Legs Hirsch!