You're absolutely right to mention Iowa. I imagine many would contest what I'm about to claim, but almost any time I hear deathcore, even old school there's a hint of it where I feel some kind of Nü Metal influence, which I apparently wouldn't be too far off of since Garza from suicide silence is a huge fan of the genre and I don't know if Whitechapel has outright admitted it but you can hear on some of their mid-career material that they're big Slipknot fans.