I would've thought they would've been, but also back in the day there were other paygrades that werent nco positions.
You used to could go up in the specialist rank to SP4 I think, so you would know as much as a SFC but wouldn't be in a leadership spot. That was how the Army used to keep people who weren't good at leadership but still knew their job. They got rid of it because everybody is expected to be a leader, and everybody should know their job, so it became kind of redundant.
Not sure exactly when it was phased out, that was before my time in the Army.
