A problem I don't think I see come up in these discussions often enough is the stats/gear predicament. Current tanks are based on VIT/STR. That's what their gear has. Creating a new tank that strays from that build necessitates new gear. More gear to roll on in every dungeon/raid. More gear to clog up the roll and keep you from getting the pieces you want. The more jobs they make with more different stat builds requiring more gear sets is more development time on items each patch. More gear means more inventory space, and we've already seen the struggle with that. What about food? Will they have to adjust or add new foods with appropriate stat combinations? How does an tank using INT or MND affect the balance from party bonuses?

New stat builds aren't out of the question, I think, but there's a lot to consider, and unfortunately, I'm not sure tanks would be the first to receive that treatment.