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

Olensheim is one of the first soldiers mentioned in the book and one of Sajer's closest friends. He speaks French, like Lensen and Hals, and along with Sajer the four soldiers remain together throughout the majority of the war. When a Gross Deutchland recruiter asks for volunteers from Olensheim's transportation unit, Olensheim volunteers with the others. He trains with Sajer, goes on leave at the same time as Sajer, and is later deployed in the same unit under Hauptmann Wesreidau. Olensheim is seriously wounded at Belgorod, but he fully recovers and rejoins the unit. He is a brave man, who does not suffer from nerves or depression. Olensheim is killed during the Russian overrun of the so-called second Dnieper front; he is the first of the group to be killed.