The Atlas calc is outdated, though. It assumes the God of War world is round like our own, but it is officially drawn flat in a conccept art and recognized as having an edge that you can fall off of several times.
Also, a good piece of evidence for Helios controlling the entire luminosity is the fact that the Earth is as illuminated as our own. We know Helios represents the sun itself as per various sources, so if the Sun was not as bright as in real life, humans wouldn't receive nearly as much light.
^Just one question, Kep. Have you thought of calculating Kratos' AoE attack (Wrath of Poseidon) when in his giant form like when he fought Ares? Because when they calculated it in base form and it was Large Town level you said it would have been bigger if they had known Kratos is taller so I can imagine it's giant version giving City to Mountain level results.