Querent: Do I wave my hands and say "Suddenly, the Ogre Warrior in front of you can't take a punch as well, and also has for some reason forgotten how to use Awesome Blow, and maybe has gained a barbarian's Rage! Poof!"
Nope. In all the situations you cite, the ogre would be an ogre.
The only case where the ogre might not get a theoretical Awesome Blow ability is if, for some reason, it caused problems in the hand of a PC. However, that is much more likely to be the case for beholders, mind flayers, and other critters with really weird, powerful abilities that would be big problems if used every round throughout an adventure.
I think this discussion points out the flaw in 3e's handling of monsters as PCs. LA works fine for *some* monsters, particularly those like giants, ogres, and minotaurs, who don't have any outlandish abilities. It breaks down for really magical, weird critters.
I think the ogre is a bad example, because he's on the very simple scale for monsters. He's basically a big, dumb fighter, and I imagine that a PC write up for him would be close to, if not precisely, just taking his stat block and playing as a level X character.
However, take the troglodyte as a counter example. Let's say I create a level 1 troglodyte fighter, the equivalent of a level 6 character. He probably has around 30 hit points, not great for a fighter at that level, but not too awful. His attack bonus is 4 points behind the equivalent human fighter. That's not so good, a 20% lower chance to hit on average.
In return, the trog has an AC of about 30 or so if he carries a shield. That's before any buffs. Thanks to the wonders of a +6 natural AC bonus, he is 30% less likely to be hit than the equivalent human fighter.
So, the trog gains +6 AC for -4 on attacks and 12 to 15 hit points.
Is that an even balance? Who knows. It might be. It probably isn't. But the key is, there's no design here. It's just numbers chosen to make a good CR 1 monster clumsily converted into a character.
In the future, we'd rather *design* this stuff to do what it does, so that when you play a trog you have a fun, interesting, reasonably balanced character.
The monster trog works fine as an NPC. He can join the party, follow you as an ally, gain character levels if the DM wants a trog wizard or fighter, and so on. The key is that, to form a fun play experience over session after session, that trog doesn't work. You need a different tool.
Some monsters are much closer to being playable. Others are farther away. We'd rather create mechanics to deal with each situation, rather than try to manufacture a one size fits all solution when it's plain that monsters need wildly different changes from case to case to become usable PCs.
