Yeah, that's where he was playing at first, and I thought looked best (from the games I've seen). I agree he's been great defensively on the left, but I think not having a left-footer there hinders you playing out from the back. If you've got a proper lefty on that side, you can pass the ball in front of him, rather than to his inside foot, and he can play first time as well, doesn't always need to take the extra touch to control.
Berra's not the quickest, but 'crocked' is a bit strong. He's played almost every game for Hearts this season, it's just that the new manager has come in and decided to get rid. Personally, I think he might potentially be worth looking at, just because none of our CBs look comfortable on the left side of defence, where he fits more naturally. (I think this was part of the reason three at the back didn't work well at the start of the season - nobody was comfortable on the left of a three, having to push into the LB area)