This was a co-headlining tour for both Chimaira and Unearth, and they were switching off who played last each night, so Chimaira wasn't an "opening band". Surprised the only played that long, honestly.
And that's pretty foolish to say neither Chimaira not Uneath should be headlining shows. I've seen both of them headline in the past year, and both were absolutely incredible. And you're also doing an extreme disservice to yourself by not listening to Unearth's earlier material, primarily The Oncoming Storm.