What do you mean by refugee group?
While their flavor varies, these are groups of (usually)mostly civilians who were ported in. Not porting in with a faction is rough. A lot of them died during the first few weeks, but those that remained coalesced into groups of survivors living off the land.
If we're talking proportions, the majority of people almost anywhere are civilian with a small minority of soldiers added in. So there are quite a few. There are different kinds of refugee groups, though the most value you'd get from the starting refugees offered are more bodies. Probably a thousand or so people, I'd imagine.