Excuse me?
Naxxramas-60 T3 gear is good enough to clear the first TBC raids with. Our tanks will literally walk into Karazhan using Dreadnaught and Thunderfury. What are you smoking? T3 has and always will be among the most powerful sets in existence (with respect to their relevant expansions). Look at https://classic.wowhead.com/item=230...wisting-nether. Tell me with a straight face that's not nearly T5 levels of power.