Maggy pre-nerf is literally a joke. My guild was a fresh reroll so we had exactly 0 Naxx/AQ40 loot, my char was a boostie. I literally killed Gruul and Magtheridon (which are in their pre-nerf states) in questing blues and greens, some people in the raid were not level 70. Naxx lvl80 was easy but its not easier than T4 and Malygos and Sarth + Drakes are harder than most anything iin TBC period, Sarth 3 drakes is not even comparable.
After T7 only normal mode TOTC is comparable with TBC difficulty, everything else is just in a different league. I dunno what else to say, calling TBC harder than WOTLK for raiding is laughable.