If you ask me, being the new guy in the ODST squad and all, he would do anything the rest of the squad suggests. Which brings me to the beginning of the Campaign. After Romeo hits the crap out of the Rookie with his sniper and wakes him up, Dutch pushes him aside and tells him "Now is one of those times, where it pays to be the strong, silent type." And as I said before, the less experieced Rookie would do well to heed advice given from the older, more experienced Corporal of the squad. I guess thats one of the few things that kept him alive on his first ODST mission, not to mention spending most of the time in the city solo.