I think between that comment and saying "two frontmen", he's saying that it sounds like the reviewer is talking about Toby and Devin, not Toby and Matt.
Ah, yeah. Matt has never done vocals besides screams on any Emery records as far as I know. Their vocal lineups can be confusing. Toby is the main singer and screamer. When Devin was in the band, he pretty much equally shared the singing with Toby, and did a very small amount of screaming/yelling. Josh does some screams on the records, but he mainly does them live. And Matt does some screaming on all their records too.
Edit: And now Andy Nichols does Devin's parts live. They did make Andy a permanent member recently, didn't they?