Apparently according to Wiki Willi Henrich loosly based him on Johan Scwerdfeger as they were in the same Division.IIRC, the mcGuffin on which the plot is based is that (a) Steiner indeed received his Eisenerkreuz whereas (b) His Kompaniefuehrer (recently appointed, by nature a spineless, ambitious and deceitful desk-jockey) has not, and covets one fiercely whilst perpetually overcome by Olympic-standard envy directed at the fine, upstanding, seasoned NCO that is Steiner. Whom he ultimately betrays - along with most, if not all, of his closest comrades.
Scwerdfeger appears to be absolutly nails. Won the Knights Cross as a Feldwebel in 1943 and the Oak Leaves a year later in 1944.
Born in 1914. Died in 2015 aged 101.
There can't have been many NCOs who were awarded both the Knights Cross and Oak Leaves.