The truth is, up until this point, Washington (ranked 5th) and San Diego (ranked 6th) are above average run defenses, while Oakland (ranked 13th) and San Francisco (ranked 17th) are average or barely above average.
If your reason for optimism is, "easier run defenses" coming up, then it looks like you may need to take off the rose-colored glasses for the following games:
Denver (ranked 4th), Washington (ranked 5th), St. Louis (ranked 7th), Kansas City (ranked 9th), Carolina (ranked 10th), Detroit (ranked 14th), NY Giants- twice (ranked 16th)
That's 8 games playing statistically better run defenses than San Francisco and 5 games playing statistically better run defenses than Oakland.