I don't think Edelman and Harris cancel out, at all. Edelman is their best receiver, and they really struggle to pass the ball. Harris doesn't move the needle on that even a little, even if he looks much better at running between the tackles than Sony did. They're completely one-dimensional now. The goal line sequence summed everything up; they ran it up the middle four straight times and gained nothing. That's the only club in their bag and when it's not working, forget about it. They can't run outside, they can't throw anywhere, it's ugly.
It's also important to keep in mind that the offense last year was a tale of two halves. The first half, the OL was a mess and the run game stunk, but they had Gordon for 6 games, AB for 1, Dorsett was playing a role he could succeed in, and the passing game was good. But once they swapped Gordon for Harry, Dorsett had to play outside more, and Sanu got hurt, they couldn't pass at all. The run game was actually OK late in the year when Wynn came back, but it didn't matter because they couldn't throw. It's basically the same story this year as it was the last 8-9 games last year, just a little more dramatic.