Tanks that pull like that in regular dungeons are just overcompensating tanks who more or less are horrible in regular play with little to no understanding of how to run a dungeon. I feel bad for people leveling up chars now that have to deal with this because its not only annoying but also usually slows the dungeon down. Thats why I say boot them until they learn, tanks like that are a dime a dozen and groupfinder will replace them within a minute