As soon as your tank gets better avoidance-stats and a bit more health you should have no problems at all, I guess.
In the beginning I was running COT4 for my first time and the infinite mobs dealt so much damage I didn't know what to do and how to survive that even though they couldn't crit me at all. 4 Mobs and I was practically dead almost every time.
After two wipes or so the healer decided to spam-heal me so I would decide - it worked but he wiped on the third boss alot since I was totally new to the instance and nobody thought it would be useful to explain a thing or more to me. Sad and cruel beginning for a tank ...