The accuracy seems very high for a cruise missile strike. Even with Tomahawks there are usually a few more misses or failures. One might have gone down in the dunes but the rest seem to have hit their targets - and that series of hits on those tanks, all in almost the same position - is a sort of accuracy that rivals the US & Russia.
Given that the warheads of these missiles are 200kg+, wouldn't there have been more visible damage? It leads me to believe that the hits on the tanks were some other sort of loitering munition/drone, but the Iranians to my knowledge don't have any Harop-style loitering munitions with the range to pull off an attack like that from Yemen or Iraq. In any case, coordinating an attack with dozens of missiles and drones so that they early detection by air defense and impact the target at around the same time - with the aforementioned high degree of accuracy - is not impossible, but that's a level of sophistication I wouldn't normally expect in the region. IMO either Saudi air defense is very incompetent - long-range drones aren't exactly hard to spot and shoot down - or some of the munitions were smuggled in and launched from within the country.