They may be old but they are known for their high-level aggressiveness in D and that's all the Lakers need that had been missing last year.
Offense is not much of a problem with WB, Lebron, Melo, and Davis.
Dwight is also a good backup for AD, to avoid stressing his injuries and give him minutes to rest. I just realized they are now filled with big men. Giants.
They have also Marc Gasol, another big men who has experienced as well, and a threat to the outside. He didn't get a good exposure last season, but I'm sure Vogel will insert him if needed as we have seen in the playoffs against the Suns as he hit crucial 3. They let go of Caruso, but added Ariza to play the defense for them against shooting guards of the opposing team.
Until Mark Gasol prove his worth with the Lakers, then I might start believing that he is still a good piece for their success. Gasol is good, no doubt about it as he already won a championship back in Toronto Raptors, but playing with Lebron could be different so he might not fit with his current team.