So what unifies these six members (Cruz, Hawley, Hyde-Smith, Kennedy, Marshall, Tuberville)? The most important thing is that they are all fairly new members. I think Cruz is most tenured among them, and he was first elected in 2012. Kennedy was class of 2016, Hyde-Smith and Hawley in the class of 2018, and Marshall and Tuberville were elected in 2020. Tuberville won in part because Trump endorsed him over Jeff Sessions in the primary.
