Nash never shows up on defense? I hope that you are only exaggerating for emphasis. Every year Nash is among league leaders in drawing offensive fouls, which is one of the most effective defensive plays you can make, since it gives the ball back to your team (and gets opposing players in foul trouble). You talk about not wanting to ignore the negative aspects of his game, but in doing so you have ignored any positive that Nash brings on defense as if he is completely useless there.Nash never shows up on defense and there is no upside to his defensive game.
As for the debate on who hurts the team more on defense, Nash or Amare, doesn't that depend on which position is more important defensively? You could have the best defensive point guard in the league, but if your interior defenders were Amare and Shaq, or Amare and Lopez/Frye as it may be this year, you will still get burned by opposing guards having big scoring games. There are many players in this league that simply cannot be guarded one-on-one no matter how great the defending guard is.
Would we be a better defensive team if Nash were a better defender? Sure. But the improvement would be small compared to the improvement if we were to replace Amare with a better defensive big, imo. And then you also have to consider what would happen on the offensive end with a defensive point guard who doesn't have the ability to distribute the ball like Nash and give his teammates easy baskets. Because it is not just defense that matters obviously, you still have to score points on the other end. How good you need to be defensively is directly related to how good you are offensively.
So which combination does everyone think would make our current team better, taking into account both offense and defense:
- Replace Nash with a great defensive point guard with very limited offensive skills and keep Amare as the primary big man, or,
- Replace Amare with a great defensive big man with very limited offensive skills and keep Nash as the point guard