Best Very Prolific Vocalist - Rob Rock

First let me say that there are very few better vocalists period. Rob Rock is a truly world-class vocalist. 

But what I'm talking about is: vocalists who put out a lot of material with a lot of different bands/projects. 

Some who come to mind for example:

Jorn Lande

Dale Thompson

Rob Rock

Tim Owens


In that vein. Rob Rock stands out greatly for the quality of the projects and the quality/effort of his vocals.

Jorn Lande is a part of some of the greatest bands/projects ever and his peak might be the highest, but he's on a lot of stuff that's "meh" to me including most of his solo stuff. 

The opposite is true for RR - especially his solo stuff which is unreal.

Rob Rock is amazing. As are all the others you mentioned. 

My favorite vocalists are Rob Halford, Ripper Owens, Eric Adams and Dale Thompson.