Agro mechanics were based on a number of factors, of which actual spell damage was one of the least impactful. Anything diseased based and long duration (things DC had quite specifically) generated massive amounts of more agro and the one tick of damage kept you bumped on the hate list. DC was fast to cast and cost basically no mana, making it the god tool of agro generation (and train creation thanks to being a disease based DoT). Combined with FD it made for being a pretty good pulling tool, as well. I remember demoing to my main enchanter in the Bear pits, having mim mez a bear for a full two minutes and then sit next to it and wait for it to wear off. Once speed cast of DC from across the room and the bear did not even give a shit he was there. It was probably too strong, but it was also pretty much the only thing SKs brought to the table, pre Luclin.
We ran a 4-6 alt crew for locking down Nag and Vox for the epic drops to trade with others and really all we needed was one gnome SK, a healer, and my rogue to win the fight (with buffs and proper resists) with maybe a mage tossed in to mana drain vox. I could go full rape mode with my Rogue and the mobs would never even look at me as long as the gnome SK we had spammed DC regularly, even after the nerf. The spell was that central to our function.
I got by in EQ because I could pull extremely well, I knew the game mechanics well enough to abuse the class, and I was the guild leader. Shadow Knight (esp the double whammy of being a DE SK for XP) were easily the worst class during the entire run of the game. Maybe mages were worse, if you took COTH away from them and mana drain for certain fights. Everything we ended up being good at was purely accidental and not dev intention.