I'm doing the same (DBC).
I'm going with Seattle for the next 2 weeks (vs TB & SF). I'm doing this because I will be away from my team and won't be able to pick up anyone different for the 3rd week of the season. The next 2 games for Seattle seem pretty good. Otherwise, yes, I would have plugged in NO vs SF.
I planned on using this strategy unless a top tier DEF landed in my lap during the draft (which it did not).
I am a 100% backer of this strategy. Why waste a pick on a DEF unless you get the best. Even with the best, you still have bad matchups...