You could also keep a key bound for only your slaves to move forward.
Then if you run through the mob and they still aren't close enough you can tap the key a few times to get them closer while your tank is building agro.
On the bard: I have a bard in my group and it grabs agro more often than the other classes...so it has to be doing something.
But since I'm a slacker and haven't installed that mod Noxxy was talking about, I don't have a clue what. :P
That being said...since I found the new spell/song that I got about 5 levels ago to reduce group agro if not a fighter..I haven't lost agro on the tank yet.