This is Sergeant Hawk. He is the leader of the squad as well as being a sniper. He prefers to destroy things from afar, so he became a sniper.
This is Eagle. He is equipped with a jetpack, and likes to swoop in on separatist forces and destroy them with his ion gun and other heavy weaponry.
This is Falcon. He is a former lancer trooper. After the Battle of Muunilist, he was chosen to be trained by Anakin Skywalker as an amazing pilot. He loves to ride extremely fast speeders and destroy droids with his pole gun.
This is Owl. He is the wiser, quieter member of the squad. He is a slicer, medic, and does not take part in much of the "dirty work". Instead, he prefers to destroy ships in a more subtle way.