The "Armenian" and "Arminian" demoninations have been confused with each other in the past. What's funny is that the Germanic name "Arminius" has Armenian roots; in 9 AD, Armenian German-hired mercenaries, led by someone known as "Arminius", defeated three Roman legions. This victory and Arminius became legendary in Germanic history. The name became widespread, with a number of forms (Armin, Arminius, Herrmann, and more).
And, as is tradition in Germanic literature, characters in sagas are either historical figures or based on historical figures. I.E. in "Atlatsvida" they group Attilla the Hun with many notable Scandinavians, most of which lived in different eras. So, interestingly, Seigfried in "The Ring of the Nibelungen" and the "Nibelungenleid" are based off of Arminius.
Quite an important character in the most prominent of Viking literary works...