No, that's just relativizing, meant to dismiss any real concern.
In other words, that line of argument can be boiled down to "whatever the players do, the DM can counteract it"
While this is true, it also draws attention away from the discussion at hand.
Also, you're forgetting you simply don't use the feat when it isn't beneficial for you.
Of course you're right in there. But an ASI is always useful. GWM not always.
Unless all or most enemies have AC 18 your argument simply isn't relevant.
Of course they don't. Where would be the fun in that? The feat is there for something and it should stay relevant all game long. Not all enemies need a high AC. Only the front liners. Just like the players. Monsters can have their tank too you know?
And if you feel compelled to increase AC to Orog levels in general, you are actually making a pretty compelling argument the feat *is* overpowered...
Why would I do such a thing with every orogs? Variation is what makes D&D a great game. Monster stats are not fixed for all eternity. Monsters adapts, changes and can use shields or not. Maybe some of them have heavy crossbows. Maybe they have poisoned arrows? It all depends on what you feel about what you have to do to make the game interesting and the type of group that you have.
The whole point was not: Boost all monsters AC and you'll have no problems.
The point is: Make some changes once in while. Make the players sweat without going all out against only one type of play. Force your players to review their tactics every now and then. You will suddenly notice that some feats are making some strange appearences, like the sentinel feat or the shield master feat...
My point is still valid. These feats are as Over Powered as you let them to be. Not all orcs encounters need to be the same. You meet 12 orogs. Are they all standard? Are there some orc veterans among them? Could there be a priestess of Luthic hidden among them? Maybe there are one or two orogs veterans (use veteran stats, gladiator?) who knows? With many DM, it will be 12 normal orogs period. That is where some feat comes in with their big shoes. The more predictable an encounter is, the more these feats will look unbalanced.
Enemies retreating behind a corner to negate a sharp shooter isn't that hard to do. No modifications are required on the monsters stats to do that. Two front row hobgoblins using the defense options while their friends shoot the GWM down, or the GWM friends is also quite an acceptable tactic. It is also a nice way to negate any advantages the pc might had.
No, I don't feel compel to shut down the feat with artificial means since I see no problems with the feat. I just use some different tactics than what is written in the monster block to push the players to their limit.
In one battle the GWM will be cleaving through the enemies like a hot knife in butter, the next, he will struggle to simply get a hit. That is where the warlock/wizard/sorcerer will come in and say:"Fireball, anyone?"
