Garth Ennis has never seemed "out there" to me. His stuff is raw, violent, and real. But, he never touches the smoke like Morrison. Grant will just float off into ethereal-monkey-gods land or something. I think his run on JLA was the most 'grounded' he ever held it...
I see you're distinction, but Ennis is pretty extreme and out there, just in a different way. Though its not ethereal monkey gods, my first thought, when I initially typed his name, was the scene in
Preacher with Odin Quincannon:


when he is caught fucking a giant woman made of ground meat.