Main problem with tanks is I find a lot of tanks lack the basic necessary skills for higher dungeons mainly due to doing fate farms up to high 40s then trying out a dungeon and failing miserably. I have no problem if I have to tell the tank about certain mechanics this dungeon has, but the thing I DO expect him to be able to do is know how to use his basic rotations of his skills and hold his aggro. I've had tanks who don't even know how to hold aggro on a boss somehow and that's just 1 mob to look after...