This one's a mismatch imo. Wan is much more digestible and fits into our typical horror expectations. Rob Zombie gives us entertaining movies but I've never felt like his stuff is actually scary so much as it's plain old twisted. I've got a soft spot for Zombie in that his work kinda reminds me of Texas Chainsaw Massacre inspired films (and TCM is my all time favorite horror). But I think Wan has the better films overall and the scarier ones as well.
What I will say though is that if you want to go outside of the box or need something different...Rob Zombie is clutch there. I enjoyed that movie 23 or 31 or whatever way more than I'd think I would for a popcorn horror that's more action than horror. He gave us an attempt at turning the Running Man into a horror-comedy movie...I don't believe anyone else would have taken that kinda approach and actually made me play around with ideas for a concept like that.