In my little patch of Sussex we have magpies, collared doves and woodpigeons and numerous small brown birds (inlcuding an, ahem, active group of dunnocks) all living together quite happily. But then that's the tolerance and diversity of Brighton for you.
Interesting. We have a both magpies and collared doves nesting in the garden - and quite a few other species as well - and I've never seen a stand-off between the doves and the magpies. The collared doves nest on top of our neighbours' Sky dish which is open to aerial predation and as far as I can tell the magpies leave them alone.