Mercenaries
A Mercenary is a soldier who hires his or herself out to another military or private interest for a profit. The use of Mercenaries can date back as far as the time of the ancient Egyptians, who often hired mercenaries to supplement their armies. In more recent times, Mercenaries have seen use in conflicts in Africa and the Middle East.
In Tomb Raider: Legend, Lara frequently encounters mercenaries hired by James W. Rutland Jr. to assist himself and Amanda Evert in locating pieces of the legendary sword Excalibur. In this role, they act as their primary security force, interfering with Lara's attempts to find the sword. They are also used to intimidate villagers in Peru and launch an assault against an isolated Kazakhstan military base.
Larson's bio in Tomb Raider: Anniversary states that he became a mercenary after serving time in a military prison, gaining a favorable reputation. In 1996, he takes work from Natla to find parts of the Scion. Before that time, he may have been working for Pierre or with him for an unknown third party to find the Philosophers Stone.