As Danny always says in response to any question he receives about team "needs", "I want guys who can play, whatever their position". The NBA is unique in that there are many different ways to skin a cat, the key is having high quality players who can play well together. Any detailed comparison to last year's pieces, or even theoretical pieces, misses this main point.
Now one could argue that Joe Smith let's say, is a better player than Marbury, something I, and I know Danny would disagree with, but frontcourt vs. backcourt is not a consideration if there is a considerable talent upgrade available. Seeing our team as thin up front or at the wing as the sole reason to go after bigs and wings, regardless of their quality, has been rejected in DA's philosophy in favor of obtaining impact players no matter what their position, which he believes Marbury is.
I think DA did not see any huge upgrades to what he already has talent-wise, not position-wise, to justify bringing in someone new to the mix besides Moore and Marbury. The fit is oh so important in a winning team, it is a delicate balance. The only circumstance that can justify upsetting it is if you can significantly upgrade your talent, which I believe DA thinks he did in swapping out POB and Cassell for Moore and Marbury. In fact, it is still going to be a struggle to fit those 2 guys in, but the risk is worth it. Adding a mediocre big or wing that does not significantly upgrade the talent already on the roster, just complicates the fit issue, but without the benefit of having better talent.