Complex sentence: Even though South Callaway has a strong rivalry with the North Callaway Thunderbirds, they are also rivals with the other people in their conference, people like the Southern Boone Eagles, the Tipton Cardinals, the Hallsville Indians, and the Harrisburg Bulldogs.
Split into simpler sentences: Even though South Callaway has a strong rivalry with the North Callaway Thunderbirds, they are also rivals with the other people in their conference. People like the Southern Boone Eagles, the Tipton Cardinals, the Hallsville Indians, and the Harrisburg Bulldogs.