If you are looking at the run defense and that's your measurement—which you have referred to often—versus looking at total defense you're looking at a spot on a picture rather than the entire work. If that measurement/spot is a negative, it is by definition sapping positive sapping the positive.
You have truth and fiction mixed in together here. It's true, "they are just numbers." Which is why your mention of those rushing yards lacks merit. It's a fraction of a larger number. BUT, more importantly here.
I sledom refer to a simple number when I'm referring to a statistical measurements. Here's a ranking.
How often have I used the word "efficiency?" That does tell the story more often, far more often, than not. Think about this. It's what I was pointing to with Vandy, and Tennessee, when we talked about those games before and after they happened.
Now, there are four major tracked measurements on defensive output: run, pass, total, and scoring. All four are mentioned.