I noticed that MFL added it to their "Set Lineup" page. So, for example, if I'm choosing between two QB's, I not only see their points, PPG, and projected points (which comes from Fantasy Sharks or some other site), but also what their current opponent gives up (average) to that position. I don't give it much attention, but in a situation where I'm comparing two players that are very close, I'll glance at it. And, it's a hyperlink, so if I click on it, it gives me a breakdown of that team's performance, fantasy-wise, against the position in question. Once you get into that breakdown, there's a dropdown box where you can select any team, and see what they give up to any position (another filter/dropdown).
I know that's not exactly what you're looking for, but it's a round-about way of seeing what CAR is giving up to LB's, for example. What I haven't figured out is if there is a way to see some sort of ranking or list of all teams, as opposed to just viewing one at a time.