Ok cool, so you have a lot of experience - how do you justify rolling each individual creature's HP and tracking it for every encounter over thousands of meaningless (sorry players!) encounters when its just there to give a little zazz to the game, get some XP, add some story, some items maybe, and now that theyre down some resources have a real fight that matters? Will I update a character sheet where its a creature 14 ac and 32 hp and a +5 to attack doing 1d6 and say these creatures at all 16ac, 40 hp, +7 to acck and its 1d6+3 damage? Yeah. But treating them as individuals? I honestly am interested in hearing how swapping HP and maintaining the same NUMBER you planned for combatants and saying "I dont care what I roll for these 5 creatures, I chose 5, and ill stick to that max hp or minimum hp" and theyre gonna have a cake-walk (kind of a waste of time) a normal or a hard (why was that so hard, we are just on our way to take a poop in the woods?). Because, again, DPR with an enemy that you cant quite kill in the same round economy means DPR is up, theyre taking N% more damage per round just with a little change that keeps 25% of the force alive 2 rounds more and now youre looking at lethal. Or...just follow the book. You want a harder fight? Swap in some hobgoblins. Add some wolves. Keep the headcount low and increase difficulty with abilities or auras, or any of the things the MM gives you. Adding a bunch of HP just to drag it out is just time consuming and miserable and rolling for the honor of wasting a bunch of time on a meaningless encounter...I don't see the upside.

What is the problem you are solving? Does your proposed change solve the problem? Is your change feasible? What else will be affected by your change? Will your change impact revenue? Does your change align with the goals and strategies of the organizations (Larian, WotC)?