Yes, you are correct, Jimmy sacrifices O for D. However, that sacrifice should not be mindless, it should be based upon risk v reward. Mookie and JSouth early did not bring enough potential reward to offset the risk, plus we had other alternatives at their positions.
You have to look at DC2's potential upside v how much worse he might be as a defender than Rak.
No question, at day one DC2 will be a much worse defender. He will never be the shot-blocker that Rak is, but there is no reason he can't be an Arinze type of space eater. However, if he gets some PT, which will give him experience and also help him get into better shape what would his game look at come next March ??? IMHO, DC2 has 3x the O upside of Rak plus he is a better rebounder, and there is no reason why he can't be at least 90% as good a defender given experience and conditioning.
The problem I have with Jimmy is not his preference for D to O, it is that sometimes he is too short-sighted. Take this season, eg, I felt (injury aside) that DC2 should have been getting more minutes all along. It is very true that had that been done, we might not have gotten to the FF. However, let's just say for argument's sake that DC2 had improved w PT into the player almost everybody on this forum thinks he might become (think Arinze as a soph for the time being) & we had gotten to the Mich game in the FF. Does anybody doubt that an effective DC2 would not have been the difference in that game ??
Jimmy coaches to max his chances to win each individual game, I think in order to win championships that sometimes you have to risk individual games to seek long term improvement.