Exactly. I can't remember who the poster was who has harped on this a number of times, but with McGahee you have a formidible run game so teams can't just tee-off on Bledsoe. We have a back who can chip block and catch out of the back field and even picks up three or four yards on first down. Couple that with fewer offsides penalties, and you're suddenly second and six instead of first and fifteen.
That relieves the pressure on Bledsoe, buys him more time...etc...etc...etc...
This is one of the reason a lot of us are holding out hope that our steady improvements in offensive performance are not a fluke but rather, as you say, a trend.