Inferno tactics.

No, brother, Gogs fit the creator's vision. When there are external Gogs, it's awesome. They are mid-tier archers, but there are many of them. And their ability to hit adjacent troops is exactly what Inferno needs.

No, I completely agree with that... :)
I'm just saying that in your battle, those 40-odd units clearly didn't make a difference... although, perhaps demons reforged from them wouldn't have helped much either.

I still haven't understood the creator's intention - why is such a demonology needed?

Well, maybe it was intended that on small maps, where there are many resources and the final battle happens relatively quickly, extra level 4 units would be very useful...