Yep, agree with that, but you have to bear in mind that there were quite a number of defensive comings and goings thro last season - eg Forsyth, Devlin, Creaney, Urquhart, etc., I can't help feel though that a decent centre-back and 'keeper should be high on the list, in addition to another midfielder and striker.
The goals against weren't all down to the one cause, and I think we need to have options in a few areas, difficult in a small squad I know. If last season taught us anything, it was that the cover has to be reasonable.