Hi Daniel,
Your fish are indeed still rather young. They could therefore perhaps be any of the phoenicurus/tweediei/rubrimontis group simply judging from the coloration. For a species determination the fish need to grow for at least some weeks or rather a few months. Once they start displaying and mating you will likely be able to get better Determination.
Your pictures are very good by the way!
Time will also shof if you actually have both sexes. Nevertheless I think that you likely have both in the pictures. If you compare the dorsal and ventral fins, the fins of second fish seem to be less round. That might be an early indication. If these were some of my tweediei I’d be pretty sure this is a couple 🙂
However Id suggest you temporarily name them phoenicurus as the importer did. This is at the moment our best clue.
Greetings Rafael