The Balrog vs The Witch King

[Raynor]

Originally Posted by Mansun

Enhanced enough to be able to have a good chance of taking care of Gandalf.

We have no evidence that the balrog relied on the blade to take care of Gandalf.

Or why bother provoking him when he can quite easily go back to sleep unharmed?

The ring for example, as you mentioned. Also, the fellowship would have been quite happy to just get away safely, regardless how many times they were provoked. They have little if any incentive in starting a fight.