[Endoperez]

It's more about the scrying and less about the accuracy. You'll see all provinces under your domain as if you had a scout in them. You won't get any more information even if you have three sources to the same information (a scout (1) in a neighbouring province (2) under your dominion (3)). You'd need a Spy (which Arcos can't recruit) or an Astral Window spell for a more accurate report.