I also try to avoid having multiple players from the same team. Actually, having and starting are two different things. If you start LT, Gates and McCardell, you better hope there are a lot of touchdowns going around. If San Diego has a bad game, so will you. Having McCardell on your bench, however, might not be bad.
Moving on, it's tough to say don't start either LT or Gates based on the argument that "it's nice not to have multiple players from the same team". LT and Gate are, to most, the best players at their respective positions. So, regarding those two: start 'em with pride. And McCardell, you may want to start another WR.
"Happy life day!"