Having a RB covered by a LB in space should be considered a matchup win against all but a couple LBs across the league. The difference with Atlanta is that they have two RBs talented enough that they make you pay not with a 5 yard completion, but with 20+ yard gashes with some regularity. As is usually the case, this gameplan is impossible for most due to the requirement of talent - most teams don't have 2 RBs as talented in space and between the tackles as Coleman / Freeman. That includes us, which is fine. We can attack the same weakness in Denver's D in different ways.
Losing Trevathian really hurt the Broncos, after yesterday I think we can safely say that. He was the LB that they leaned on to make plays against RBs and TEs, because he was the guy that they could lean on to make plays on that level without having to take Miller out of the pass rush. It'll be really interesting to see what they do against the Pats; wouldn't surprise me if the Broncos use Miller in coverage a lot, and hope that Ware/Ray/Barrett are enough to get a strong pass rush on their own. I don't see how else the Broncos match up with Gronk and Bennett. They won't be able to sell out on Gronk like they traditionally have, because that just creates a repeat of yesterday: defense throws the kitchen sink at making sure Gronk doesn't get the ball anywhere near the goal line, and that just leads to Bennett walking into the end zone untouched.