Originally Posted by Isaku900
these two statements are a contradiction. If your narrow stance squat is stronger than your wide stance, and your lower back is a huge limiting factor, then your posterior chain is weaker.
My back is actually my strongest point. I just found that it was mostly my back taking the load with low-bar squats, rather than my legs. With a narrower stance, I find my leg muscles are more fully activated and I can move more weight.