Centre Peel vs Line Peel
Determining which peel to use is situational.
A centre peel is used when the squad encounters an overwhelming force from the front, especially in staggered column, and needs to withdraw to their rear, this is used when the best direction of movement is rear. This will be used when operating in urban terrain and you need to move back down a street or in open terrain where natural cover and concealment is to the rear.
A line peel is used when the squad encounters an overwhelming force from the front and needs to withdraw to cover on their right or left. This will be used in urban terrain when moving off a main street onto a side road or when out in the open to move towards natural cover and concealment.