Actually they got Nash before Dwight. Pau was on the block and he got injured and therefore could not be traded.
Dwight is much better in the pick and roll than the post.
It happened shortly before they got Dwight. It was very poor planning in general to add another old player into the group, even without Dwight in mind. But, you wait to make other moves when you have a major trade in the works. Pau wasn't on the trading block at all during the season. It was said that they wanted to see Nash back before they made any moves, which was laughable considering how awful they looked.
I honestly hope I'm wrong about Jim, but the Lakers have declined faster and faster with each year. The Lakers' past history doesn't really matter. Bad management ruins great franchises all the time. And, the Lakers management has looked awful the last few years.