At some point between TAR14 and TAR18, Jodi (of Christie &) was put in charge of casting for the show (or at the very least, she had a high-ranking position in the casting department). As such, when it came to casting TAR18, Jodi went with people she knew and had become friends with, and that's why you get Amanda & Kris, Mel & Mike, Kisha & Jen, Margie & Luke, and Jaime & Cara making up almost half the cast.