I think it's a question of options, rather than power.
A sufficiently powerful entity could probably over-awe and conquer a small nation with ease...but if they did so directly, they wouldn't survive human retaliation. Given enough numbers and incentive, the default assumption in the Dresdenverse is humans win...against anything. Oh yes, they would take a horrible beating and thousands of soldiers/civilians would die; but so would, say, Ferrovax.
Which is why the supernatural players work together to keep things secret.
Spell-casters are the sterotypical glass cannons in a direct conflict; 3-5 effects, and they're staggering, which means again, sufficient numbers can wear them down pretty quickly. Thaumaturgy changes things, but takes time to prepare.
Your basic caster, from the start, can throw battlefield-level damage evocations; the question is, how long can they keep doing that? 4-5 tanks, maybe. And what about missiles and other objects moving too fast to be seen, and exploding too far away to be hexed?
Evocation and Thuamaturgy are force-multipliers, allowing for casters to apply force far beyond what similar refresh powers can accomplish...at least for short bursts.
So, it depends on the type of conflict. In a direct, stand-up type of fight, direct powers (Inhuman/Superhuman/Mythic) levels of Strength/Speed/ Toughness count for a lot more. In any contest where there's time to prepare, casters refresh is equivalent to 2x to 3x the equivalent refresh of any other powers...at least.
In last two examples, I think you're talking ludicrous levels of Refresh for a supernatural monster...or maybe 12-15 refresh for casters.