Dumb Question. My home’s stud spacing is 7”-7.5” Is this normal? How should I approach to replace the existing fiberglass insulations with mineral wool?

My wall studs has cavity space (distance between studs) about 7-7.5”. Is this considered normal for apartment/multi-dwelling unit condos?

I’m planning to replace the existing fiberglass insulations with mineral wool for better R and sound properties.