I usually only have 1 at most, but usually I just turn up and even now there's usually people around, and just doing the fights drops some so you can contribute too.
I haven't been back to the rune place yet, though that might be a good idea. I bet some of those fights would be much easier now.
I really like those zones because it's a way to join in some co-op multiplayer fun without ever feeling committed. If you want to sit one out, you can, if you want to leave after one, that's fine, and the drops are pretty good. I hope they do more of that for Destiny 2