Unfortunately, that is exactly the problem with Armenian literature today. There are genuine literary treasures that can stand shoulder to shoulder with other great literary works of the world, but neglect and a deep, immovable indifference (first and foremost on the part of Armenians, hence the fourth grade translations) keep them locked away in the basement of world literature.
I believe there was in fact a very admirable translation of Sasna Tsrer by Artin Shalian titled David of Sassoun: The Armenian Folk Epic in Four Cycles published by the Ohio University Press in 1964. But, of course, the book languishes, unrecognized and unappreciated, out of print, collecting dust on university library shelves.
https://archive.org/details/davidofsassounar00shalrich
Speaking of paganism, Shalian also wrote a book on Armenian folklore titled Pagan Idylls (which I have not yet read and is difficult to come by) which is in the same boat.