@Saf:
I am not sure you are taking the character of these opponents into consideration. One is a member of the Blue Dragonflight: One of the most intelligent and learned factions in this game. He may fall for the Elementium Bulwark once, but since Ozruk calls it out every time he casts it, it won't be hard to avoid after the first time.

"Blue dragons are not cruel beasts, preferring a quick kill for enemies and prey alike. They often use their abilities and spells from afar... They are excellent tacticians and attempt to damage or disable any opposing spellcasters before they commit to a physical attack. Blue dragons prefer to fight from the air, using spells and breath weapons to their fullest." -via Wowpedia

Now normally that would mean paralyze+flying = fall. However certain rules prohibit flying, so Eregos will just keep his distance and be paralyzed at range. Oz always follows his paralyze immediately with a shatter (before closing any distance), making it useless against ranged foe (technically the whelps will all be ranged too). He will take the damage when the debuff wears off, which is hefty, but not devastating to a boss.

Ground Smash can also be sidestepped thanks to its 3 sec cast. So again, he will only get one off before Eregos learns how to out maneuver it.

Looking at Ozruk, we see he is a rock, which is as dumb as...a rock:
"Ozruk has served as Stonecore's guardian since Deepholm's creation. It is unknown why Ozruk has remained in the Stonecore, but it has become apparent that the guardian now believes that anyone opposed to Deathwing is a threat to Deepholm, and should therefore be destroyed." -Wowpedia

So he now aligns himself with Deathwing despite his shattering of the World Pillar which endangered the World's Heart to begin with. Ozruk is clearly the dullest in a series of very dull tools. As such I imagine he will just blindly go through his rotation without strategy, which is very easy to plan around.