You definitely see the glass half full, which is a noble characteristic. But on your thought of enough oil being pulled in the right crank seal to cancel the lean condition from the leaking left crank seal, uh, no. We all wish this is the way it would work in real life, but it doesn't. Air is easier to pull in than oil and your vacuum is going to pull in air through the left seal more so than oil through the right seal, assuming the seal integrity is weakened exactly the same on both sides. Now we all know both seals probably weren't weakened exactly the same. Maybe in some Utopia the right seal was proportionately worse than the left seal to allow the engine to pull corresponding amounts of oil from right and air from left, well that would bring us to the next point: Lean condition denotes too much air compared to atomized gasoline in your mixture. While it seems the addition of extra oil might mitigate damage, not really. A lean burn is a hotter burn, extra oil or not.
Of course, I'm sometimes wrong.