Pally OT's unbuffed stats are fine for heroic Patchwerk. As long as a tank has enough HP to soak a Hateful without getting one-shot, anything above that is just a tiny bit of padding in case the healers fall behind on a rotation. The fight is long enough that if you're not healing them to full after each Hateful Strike before they eat the next one, eventually you're going to wipe through attrition anyways.
Assuming your tanks aren't all badly undergeared, Patchwerk is all about the healing. Even though you've got 3 targets in 25-man, it basically functions as though all of your healers are healing the same person and if any of those healers fall behind, you wipe. The reason I say that is because Patchwerk uses Hateful Strike every second and in 25-man, he uses it on the player who has the most HP out of the second and third person on his threat list. That means that if your pally OT eats a Hateful Strike and the other OT is at full health, the other OT will eat the next Hateful Strike one second later. Assuming the healers were able to top up the pally OT, he'll eat the next Hateful Strike. Back and forth it goes until one of the tanks dies or Patchwerk dies. If the healers on the pally are doing a good job but the healers on the other OT are falling behind, the pally can end up eating two Hatefuls in a row, and that's bad mojo. Very bad mojo. Fully raid buffed my pally can handle two Hatefuls in a row and barely survive, but I'm about maxed out for iLevel 213 gear so that's not a standard I would expect most pallies or warriors to be able to live up to if you're progressing through Naxx.
Edit: I can't quite manage two Hatefuls with no healing in between. They were hitting me tonight for ~20k damage and I topped out at about 37k HP fully raid buffed. It just goes to show that even if your tanks are maxed out (or very close to maxed out) with current raid epics, paladins and warriors are good for one Hateful Strike and the second will gibb them if they don't get any heals. If you're falling behind in the heals by 3k every cycle, you won't make it for the duration of the fight.
The key to healing Patchwerk is to overheal like a ****. Don't wait for the health bar to drop to start casting your next heal. Expect that every two seconds your tank is going to take a massive hit and assume that you've only got 1 second to top them off before they take the next one. Don't worry about overhealing...as long as you've got mana, keep spamming the heals. If you're running low on mana, pot/Innervate/whatever to make sure that you can keep spamming the heals. If your tank manages to dodge/parry a Hateful, awesome..ideally, that should be happening almost half the time even for pally/warrior tanks, but don't count on it. (I've Dodged/Parried 8 Hatefuls in a row but RNG can just as quickly ***** you over as it can save you). Assuming you've got all of your HoTs ticking, spam Nourish/Swiftmend + Healing Touch every GCD. Refresh your HoTs as necessary and repeat. Between the healing that does and the healing from the other healer on that tank, you should have no trouble getting them topped up every Hateful cycle.
Edited, Feb 26th 2009 12:14am by AureliusSir