A separate post since this is to the other main complain I see in this thread: about regen pre-pull is bad. I'll tell you this: if I am tanking and you are healing, you are welcome to put Regen + Medica II on my pre-pull, and still no mobs gonna take so much a lick on you. This is actually the issue on the tanks not doing the pull correctly. Most tanks open their pull with a range attack (i.e Tomahawk/Shield Blob/Unmend) before following up with an AOE in the 2nd attack, it's this one GCD between your first and second move that make the mobs peeline to the healer. If you are a tank with this problem, do this: run straight to the pack and do your AOE like Flash as your first attack, then you will NEVER have this problem again. The range attack on the tanks are never meant to be your opener, it's only for picking up stray mobs.
While what you say to do is definitely what you should be doing as a tank (and is what I try to do, especially nowadays), I wouldn't go quite as far as to say you'll never have the problem again. Some enemies have different detection ranges and movement speeds, both of which may throw off your AoE timing and cause you to miss mobs. I see this happen frequently with newer tanks in particular.