[PvK]

Only for certain weapons and units. Some are taken away as you describe, sometimes without a seemingly good reason. Others stay.

In this case, it probably makes sense. If you are talking about a Bane or Bane Lord, then the weapon they have by default is a two-handed Bane Blade (the 9-damage one), NOT the one-handed Bane Blade (the 6-damage one), so it makes sense they can't use it with a shield.

PvK