Nice work! It's a good, clean, basic paint job. Some of the paint looks just
a little thick, particularly the flesh tones on the second guy. It might help to water down your paints just a bit more. The shading on the muscles are nice though.
Did you use any inks or washes on these guys? Hitting them with a brown wash might not be a bad idea, to provide a bit more shading.
Besides that, the biggest, and easiest thing you can do to
really improve the look of these guys as a unit, is to finish basing them. Just some simple flock and small pebbles will go a long way to to giving them a nice, finished look. Drilling out their gun barrels with a pin vice will also help (although I admit I often used to skip this step, now that I've started drilling out barrels I find that it improves the look of things a lot!).
Also, you should upload this images to the Dakka Gallery, so we can all vote on them and you can add them to the collection!
It's always great to see some Necromunda stuff on here, and I'm hoping you post some more soon!