If you are referring to a router with a roundover bit, I used to get my wood scales as close to the size of the tang as possible and then rout the corners over with a Dremel router before attaching them.
I think its a waste of time and you run the chance of a "blowout" when the bit crosses a grain direction change like on the ends.
I've either gotten much lazier or better because now I just freehand everything and get a better elliptical profile with a slack belt. Routed corners on flat scales dont feel right to me. Just an opinion.
regards,
Steve