My left erector is even visibly bigger than my right (physio told me that during a massage). But for me this doesn't really cause problems other than occasionally some SI-joint aggravation and alignment problems. Which usually aren't very bad or painful. I think for me my biggest problem which caused this is deadlifting with a mixed grip. So that is something to look out for maybe. She said to me if I avoid deadlifting with a mixed grip (which I do) it should resolve itself.
Other things to look out for: how is your hip mobility? Are there differences in external rotation between left and right? Is maybe one of your legs shorter? Is your hip tilted or shifted in any way? Are there any mobility differences between your legs (hamstrings, hip flexors, ankles)? Did you have any injuries in the past like a torn ligament in your ankle (I have seen this suprisingly often as the cause of dysfunction issues)?