First you make no distinction from how you get your scoring. Scoring 20ppg on out side jumpers on 20 shots doesnt have near the positive effect that scoring 20ppg on 12 shots in the post has.
I wanted to be concise but let's just say "Offense" means all areas of offense (shooting, posting, passing) and "Defense" means all areas of defense (man to man, help, rotating, blocking shots, altering shots)
Second Kareem won 4 championships long past his prime with minimal defense and rebounding.
How many shots was he blocking and altering? This was a bit before my time--perhaps when the NBA was different. But I'd bet he was still a presence in the middle on D even if his lateral speed was a step slower.
Third when did Bill Cartwright and Luke Longley become great rebounders and defenders while winning all those rings?
I'd say Cartwright was at least an average defensive center.
Lastly you see to want a pg that plays no defense and a Center that plays no offense. That doesnt look to me like a title winner.
I'd prefer that to the reverse (a center who plays no D and a PG who can't run an offense) but obviously it is not ideal. You have to make sacrifices. You're not going to get fantastic two way players at all five positions. No team has that. I'm curious where people place their emphasis. For example, are you willing to sacrifice some offense from your center if he compensates with great defense? Or is the offense crucial and the defense is where you're willing to sacrifice? (I already know your answer but I'm posing the question to the board).