Who is Olensheim from The Forgotten Soldier and what is their importance?

Olensheim is one of the first soldiers Sajer mentions, and a man who became on of his closest friends. Olensheim speaks French, like Lensen and Hals, and along with Sajer the four soldiers remain together throughout most of the war. When a Gross Deutchland recruiter asks for volunteers from Olensheim's transportation unit, Olensheim volunteers to join the infantry. Sajer and Olensheim train together, go on leave together, and are deployed in the same unit under Hauptmann Wesreidau. Olensheim is seriously wounded at Belgorod, but over time, he fully recovers and rejoins the same unit. He is described as brave, but he apparently is not particularly distinguished in combat. Olensheim is killed during the Russian overrun of the second Dnieper front; he is the first of the four friends to be killed.