Rookie

-has never seen combat

-worried about messing up

-insanely good hacker

-always getting roped into snipers pranks

-you know "we were soldiers"?. And the scenes with the one soldier saying good morning to the sergeant major? Thats their relationship with the leader

Spotter

-tries (unsucessfuly) to get sniper to not prank people

-always done with snipers shit

-sharp eye and crazy attention to detail

-unashamedly likes small animals, like rodents (to the horror of sniper)

-they and dog handler have a look they give each other which translates to "everyone is fucking nuts". Another is "whos done what now?"