I'm rescuing two roborovskis, tips?

[Gaoo]

Hello everyone

Suddenly it seems like I'm taking my friend's roborovskis home with me (since his parents thing that the hamsters are in fault for the rats that are on the building, I know, makes no sense, but finally I'm taking them out of there, they're being treated as a toy).

My friend has kept them together since he got them as babies. No one knows if they are both males or both females (since they have been together for so long I think they're both the same sex) and they aren't tamed at all (more than that, they fear humans) so I don't know how easy will be to sex them.

I know robos can live in pairs or groups but I've heard that's very hard.
Shall I separate them? I'm getting them a new cage anyway (the one my friend is giving me is tiny)
Also, I already have a dwarf campbell (my cute not-that-baby-anymore Verdandi) so I now more that the basics of hamster keeping but, any tip specific to roborovskis?