Max Zander was a marine in the Confederate Marine Corps. He was hollow-faced and knew his way around a truck engine.
During the Guild Wars he was assigned to the First Squad of the Special Tactics and Mission Platoon, 321st Colonial Rangers Battalion.
He used a man-portable grenade launcher.
References
Dietz, William C. (April 6, 2010). StarCraft II: Heaven's Devils. Simon & Schuster (Gallery Books). ISBN 978-1-4165-5084-6