I think Ernie's figured it out - if you are going to play Lia and Manny together, who are both defensively decent, then you need someone who can pass out of defence because they can barely hang on to the ball, let alone pass it.
So you either bench one of them for someone who can both win the ball and link with the front half of the park and Hernandez in particular (doesn't that just sound like the player we were looking for but couldn't find) or you stick in an extra mid-fielder to play the linking role (Hicks or Reira or whoever) and drop a forward.
P.S Cunningham is taking a while to settle in to our style - which is a bit all over the place at the moment. I think once Ernie's settles on his optimum formation we might see a bit more from Cunningham. I don't buy you get to play more than a few games for Costa Rica unless you can play.