I am not so sure about Iran’s accuracy. The attack on the Aramco facility was a direct hit on several large structures that were separated by a significant distance.
https://www.sunstar.com.ph/uploads/images/2019/09/16/175837.jpg
Note the round tank structures, middle right, were almost all hit with one missile each.
If one launches a cluster of missiles at a target, even with 1/4 mile accuracy (being generous with that), one is going to hit some things.
The Saudi facility was several sq miles of tanks, pipes and equipment. All Iran had to do was point and shoot.
Not unlike rocket artillery.
