With Gates, they can do a lot of the same things the Chiefs do with Gonzalez. In particular, running mirror routes with a WR like Parker and forcing the defense to either double Gonzo or the WR or if the defense is in zone coverage, force the secondary into some tough spots. The big difference is Gonzo is a helluva blocker and Gates is pretty non-existent as a blocker.
It's kind of strange because so many people think that SD and Dallas are very similar teams since they play the 3-4 and have old school coaches. But in reality, they are almost direct opposites. Dallas has one of the most versatile offenses that throws a ton of formations at teams in the NFL. Dallas has the unique ability to utilize a 4 WR formation and still run out of that formation or go with a jumbo package and still pass out of that formation. They can go with standard fullback package or use Fasano as an H-back or use the 2 TE set, the standard 3 WR set, or go empty backfield.
But while Dallas has so many formations and can do different things out of those formations, they are probably the most vanilla defense in the league. OTOH, the Chargers are almost the direct opposite of their offense....not being afraid to stunt, zone blitz, and use all types of blitzes and coverages that allows them to get to the QB.
I think Merriman is a good player, but he's probably the 3rd best defender on the Chargers, certainly behind Jammal Williams and probably behind Luis Castillo.
YAKUZA