I think that the only time that you should consider running Great weapons, is if you have at least 15+ models to soak up any damage that could easily be accumulated by a 5+ save. Not to mention that it is slightly easier to hit the Grave Guard then most High power unit s such as this one.
As for your Battle standard, i don't like running him in my grave guard for the mere fact that i know he isnt needed there as much as he is needed near the center of the battlefield to ensure that my line of Skeletons or Zombies don't lose too much models and can at least tie at combat rez.
Once again, its all dependent upon how you want to field the army. I use the hammer and anvil tactic which was heavily developed from the old army book and merely tooled to fit the new one for me.
On the flip-side, if you want a unit that can hold its ground superbly well and deal some damage, there is no better combination than 20 graveguard with shields, a vampire (or wighty) with a battle standard and a shield, and the banner of the barrows and you have the perfect anvil unit!