While your brief analysis of the Panther's Oline has a lot of truth to it, I'm not sure it's yet fair to say that their is a problem in the 2ndary. The rooks are playing pretty well and definitely aren't the problem. Another is that they can't get a pass rush because the QBs are having success throwing the ball for short, quick, Brady esque passes, but when throwing deeper, the interior rush at least is getting there, and the corners have been impressing. While they are no Norman at this point, I can say that they are one of the few bright spots so far. The main problem is that the Oline can't block, and special teams can't tackle.
With Chris Paul's future and happiness up in the air, new general manager Dell Demps had to make a move to try and surround CP3 with more talent. Mission accomplished. Collison emerged last season when Paul was sidelined with injury and showed the potential of being a franchise-caliber point guard, making him the Hornets' best trade asset. Acquiring Ariza adds some much needed talent and versatility to the wing for New Orleans. He gives the Hornets a defensive stopper and athlete who excels in the open court although now New Orleans now has no backup for Paul.
In a separate deal, the Hornets dealt crap for crap when they acquired Marco Belinelli from Toronto for Julian Wright.
Why this makes sense for Indiana:
Indiana has been desperately seeking a point guard of the future and finds its match in Collison. It now appears that the Pacers are working on buying out veteran T.J. Ford who is in the final year of his deal. Posey is pretty much a throw-in and adds even more depth to an already-crowded small forward position that has Danny Granger, Mike Dunleavy and Paul George.
Having to trade Murphy to get a franchise point guard leaves a bit of a hole at power forward as Indiana will now have to start Tyler Hansbrough at the four and only has Josh McRoberts as a backup. Murphy was in the final year of his deal though and likely would not have re-signed with Indiana next summer.
Why this makes sense for New Jersey:
Murphy gives New Jersey a veteran power forward who can hold down the position until Derrick Favors matures into a starter. He also is a valuable trade asset since his near $12 million deal comes off the books after this season. Losing Lee means Terrence Williams likely becomes the starting two-guard with Travis Outlaw probably starting at the three.
Why this makes sense for Houston:
Houston's motivation for making this deal was purely financial as Lee is an obvious downgrade from Ariza. Since the Rockets had to open up their wallets this summer to extend Kyle Lowry and Luis Scola, and add Brad Miller, they were well over the luxury tax. This deal saves them around $5 million dollars this season but about $10 million total since they have less to pay in luxury tax.