In 2002 and 2003, we had a great perimeter defender (Doug Christie) and a good big man defender (Chris Webber, pre-injury). Bobby was healthy too, and came in for Bibby.
We traded for undersized forwards that were never known to be big on defense. Petrie is going to have to get at least 2 guys in a trade. One guy isn't going to make a good defensive team. The most likely positions for defender roles are SG and PF with our lineup.