I think they are increased the HP because they lowered the AC earlier. Some changes seem unnecessary, but in this case it makes sense.
If the Wotc approved the changes, they obviously don't mind.
No, no it doesn't make sense. The AC and HP values of enemies are carefully tailored to match that creatures expected CR value. The problem is that a few people at Larian probably never understood the mechanics of 5e or D&D, rolled badly on some attack rolls, and decided that it was no fun to "miss". So they lowered enemy AC, which fair enough. That's okay, in fact that would be a primary method of balancing gameplay Difficulty. But then they also increased enemy HP, which is stupid. Because that breaks a LOT more than just lowering AC breaks.
What Larian needs to realize is that there are plenty of methods of gaining Advantage/imposing Disadvantage during fights based on the 5e rules. Those methods have been balanced to have certain drawbacks or limitations, like the Faerie Fire spell or Barbarian Reckless or Rogue Cunning Action Hide. Each method has some sort of cost (spell slot, providing the enemy Advantage, Bonus Action and several requirements) and usually often involves some sort of Party synergy.
By introducing two no-cost methods of gaining Advantage, every single other method becomes useless. Why on earth would I ever cast Faerie Fire when I can just circle-strafe my Fighter? The amount of reliance on a good party drops off dramatically until every combat devolves to the exact same priority of:
1. Get height advantage
2. Get behind target
3. Use surfaces/shove
Fin. That's the optimal strategy for literally every fight in BG 3 right now. 1/3 of the game, no reliance on any thing else. What build you do, what your class is, any tactical efforts at party synergy, none of those matter because there are such stronger options introduced into an otherwise decently balanced rule system.
All stemming from the back that Larian didn't like to miss, but also wanted fights to last as long as DoS fights did.
