Well think about there are all strangers they came from different training centre unlike rookie blue who seem all been trained at the same place hence no bonding but i am sure after few episode they will start bonding. it's like first day in a job no-one talks to you after few week you get to know people.
I agree about the Afgan guy i have a few friends that from same place but they are the most friendly people i have ever met this guy is the complete opposite.