The newly updated Waaagh Ghazghkull supplement allows a formation-based detachment like the Necron Decurion. In it, one of the benefits is being able to Waaagh every turn so if you take Ghazghkull as part of that detachment, he can have a 2++ save all game, all meganobz can run and charge, and all orks (for the most part) are fearless.
The challenge is that the core formations needed for the detachment are expensive to field and Ghazghkull can only be used by taking his command formation which includes him, mad dok, 2 warbosses, and some nobz. Add in the requirement of an auxillary pick as well and you're hitting 1850-2000pts really quickly with not much in terms of actual killing power in your army.
So yes it can be done. It's expensive to field and is probably best for much larger point games than most people play.