I was gonna say that it makes sense keeping it the way it is, but then I remembered that the description for Power Shot was modified after the Behemoth/Force Field was added to the game. Prior to that, Power Shot simply stated that it 'ignores defensive skills and terrain' without including the word 'most'. That's an ability referring to other abilities though - it's Power Shot that bypasses the Flying ability, not the artillery unit itself. This is more apparent with the Mortar ability, which doesn't allow an artillery unit to target Flying (or stealthed) units but it can still be used to damage them if they're close enough to another unit that's being targeted.
So I guess...in the end, I'm still fine keeping it as it is. Perhaps it's just semantics, but to me it makes sense!