Нашёл довольно интересную информацию о Капитане, оказывается Ганс Гюнше - фанатское имя, а не официальное.
Фрагмент сатьи: Fans have taken to naming the Captain Hans Günsche(ハンス・ギュンシュ) after his prototype character from one of Hirano’s original Dōjinshi "Desert Schutzstaffel". It is important to note, however, that this name is only a fan name, as it has never actually been used in the Hellsing manga or OVA series to refer to the Captain in either the dialogue or any of Hirano’s written word. The name only appears once in Hellsing, spelled “Hance Ginshuu”, which would come out to “Hans Günsche” if it were written in katakana. However, this appearance of the name is written in a chapter where the Captain doesn’t make a single appearance, and is written amongst a random garble of text along with “KamFPGruppe” “Hitler” and “HaiddAdolf”. It is for this reason that it should simply be taken as a random bit of Engrish, and that until Hirano writes a name near the Captain’s picture, in the dialogue or mentions his name in an interview, the Captain's actual name is not known.
источник:
http://hellsing.wikia.com/wiki/The_Captain