Space marines tend to also have quite a few characters lying around but I'm confident that the Wolves can at least put up a good fight!
One thing that has me thinking - necrons seem like they are better for a long game strategy whereas the Wolves (and other assault oriented armies like angels) look like they are great in that melee combat but lose their momentum quickly - is that a concern for you?
RE: Warhammer 40,000 - I once more seek defeat! This time, I face the Necrons!