Alanic coat
https://hu.pinterest.com/juliuskazsmer/moschevaya-balka-coat/

Are these varangians (forth row)? I noticed the similar strapping on the chest.
http://images.google.com.au/images?hl=en&...rch+Images
http://asgard.tgorod.ru/libri.php3?cont=_caftan

The last site I linked to http://asgard.tgorod.ru/libri.php3?cont=_caftan is worth translating if you're interested in Rus burials and what type of caftans (long robes) they wore, based on the type and arrangement of buttons found in the graves.

From the site:
Anecdotal memories seem to have survived this fashion in the Norse sagas of the Viking era. For example, in the Icelandic saga of Jegile there is a reference to the cut of the rich clothing of the noble Scandinavian. About 940-960 Gg. In England, Jegilju Skallagrimsonu, a Viking leader and wealthy landowner, was given a "long garment, finishing from silk, with a golden fringe and golden buttons to the bottom" [10].

Does this matter if the painting is depicting a biblical or hagiographical scene?

The gist of the article is about comparing the caftans worn by central asians, rus, byzantines and bulgarians.

The text relating to the painting:
In the Book of ceremonial court ceremonies, Skaramangij is referred to as the favourite clothing of Byzantine military officials. The source reports that the Skaramangijah appear on the king's contenders, the so-called King's friends, and especially "friends" from the "federal" of Bulgaria [46]. By comparing this information with the image of the noble Bulgarians of Menealogija Basil II, it can be assumed that the Bulgarians in the figure are dressed in the ceremonies mentioned in the book, skaramangii (Figure 11. Zoom in) [47].

Ahh. Got it.