1st: Sorry to necro an old topic but since this is the #1 hit for the subject I figured I would elaborate upon it.
Your group should have: Sturdy MT [reliable OT not necessary but a nice addition incase MT get's swamped by a rapid barrage of attacks and healers can't keep up]; a good cleric with at least a shammy/druid backup, 2 clerics may be overkill and the SHM debuffs and DRU dots can really help, the rest of your raiding party should be ranged DPS classes, WIZ, MAG, RAN, NEC, and BER [MNK and ROG get nice crits with thrown as well, just remember, melee ranged should be treated as melee since they will still need LoS with CT and that could make them susecptible to knockbacks]. One party will have some trouble, two groups is ideal, three would be overkill but you could commit a group to crowd control of adds and respawns that may occur. I wouldn't use pets since they can cause a lot of aggro issues. If you have a T8 pet or some specialty donor or ldon thing going on, make sure pets are treated as melee and given levitate!
1st and foremost, you need levitate on your group, this will ensure the knockback only move you a few feet, it is a 100% must on tank [keeps him in aggro range even after knockback occurs]. The "Ring of Toor" found in Crushbone can provide this for you though there are better choices [this is under assumption you have nothing and this is just a quick fix suggestion]. For people boxing, I suggest having an instant click [or quick cast] item with "Dead Man Floating" on it, this will create an effective solution to the debuffs. Just be sure to have it in an open inventory space where you can make an inventory slot button on your hotbar and pay attention to when the knockback occurs, click at it until the buff lands and you'll be peachy.
2nd placement behind the large tree for heals/debuffs/& nuking toons is a must! This places them out of CT's LoS and makes them invulnerable to the knockback. The only problem is targetting, make sure your nuking/debuffing toons are targetted to CT before the beginning of the fight and just take care not to press "esc." Make sure your healers are targetting the MT and you should be fine. Technically, at ths point, you should have various items with range extension abilities and CT's target region is huge, so hitting him should not be any issue[if you are having range issues here are some items that should be fairly easily attained, items with:
Ikaav Glare http://www.thehiddenforest.org/webtools/spells.php?id=6476,
Discordant Distance http://www.thehiddenforest.org/webtools/spells.php?id=4861,
True Distance http://www.thehiddenforest.org/webtools/spells.php?id=8506,
Wurine Distance http://www.thehiddenforest.org/webtools/spells.php?id=7846,
Ancient Distance http://www.thehiddenforest.org/webtools/spells.php?id=8703, or
Chaotic Distance http://www.thehiddenforest.org/webtools/spells.php?id=8505 should solve this issue. If not, you are simply not prepared for this fight. Another option is get more AA's if that is an option for the character. Also keep in mind, you can just switch out these items simply for this battle and replace them later, so don't worry if it isn't an upgrade to what you have equipped currently.
I do not use the hourglass placement at all since it places you in LoS and you will get hit by the knockback, if you do you could end up a long ways off, but if you use this strategy, then make sure you have and keep your levitate up as explained above.
3rd Melee DPS [non-ranged] is not completely useless, if you are multi-boxing, I am sure you are using MQ. If that be the case a "/stick behind 15" + levitate will keep them in the fight. Never tried the "shrink" method, but I am sure it cannot hurt. Again there are a ton of items with this effect going back to the "Plerg Skin Cape" [or whatever that first quest item given in Paludal is called] and will only take a matter of a few minutes to aquire with a level 70. Shrink will also decrease your aggro radius and therefore decrease the chance of aggro lifting off the MT.
The Cazic-Thule battle really isn't hard, if you can beat the Avatars in Eryslai, then should be a piece of cake. Just longer. He can hit hard, but if you are repeatedly wiping on him you maybe aren't prepared well enough and should consider spending more time in the lower tiers. I can box this fight with a team of six [lengthy but easy] MT is using a mix of T3, 4, 5, and 6 gear [T6 BP + a few donor pieces] and the rest a mix of T3-5 gear with many T5 augs.
I do suggest having about 30khp and 7500+ac on MT, just to insure he can take CT's hits. This is a reasonably doable figure with T3-6 gear and T5 augs maybe some LDON stuff, like "Shoulders of the Sand Warrior." Any alternate melee types at least 25khp and 5000+ac, just to be safe incase MT gets knockback out of aggro radius for a moment and you get hit. The rest should be far removed from the battle, out of LoS, and clicking their "Charm of Queen Adrianne" the moment the MT dies [unless you have a reliable OT], so they don't get summoned to their doom anyway. So healer/nuker/doter/debuffer/ranged damage support hp/mana/ac really don't matter. The fight will be long so bring your "Orb of Spirits" and any other mana refills you have "Belt of Arbiter," etc.
And good luck!