Dark Arches

I know most of my moffy contacts are going to tell me this is a Dark Arches, as they 'duh' me while they type, but...

This is the first of many of this same size, each the same colors. So because this moth is 3/4 the size of a Dark Arches, and because I don't want to miss something I don't have any experience with, and because I seem to keep getting at least one or two of these the last week...

I'd like second opinions please :D

He has a wing size of just under 20mm.