Currently, only bards have double invis, given during the ROS expansion. Traditionally, though, enchanters were the king of invis. We got invis at level 4, and invisibility to undead at 14. No other class could compete with enchanter when it came to invis. Bards didn't get invis till level 19, and not sure when they got IVU, but it was very late in the expansions. If that doesn't convince you (class design can change), consider that bards and enchanters play a similar role in groups. It would make sense that both would have similar abilities.