Do I really have to explain why adding extra opponents to game where you have to wait for your turn is a bad idea? At this point, the worst (not difficult) encounters are the fights in which you fight a lot of enemies (like a goblin camp). Adding additional enemies will only make matters worse. The last thing I wanna do is wait 10 minutes for my turn (intentional hyperbole).
First +1 goblin not +1 horde
Second: still waiting to see your analysis regarding nerfed spells
Third: still waiting to see the reasons why you think more hp less ac makes the game harder