Iranian leadership esp IRGC is well aware of the petro dollar's weak neck which is why when they need to shake US interests to their core they attack Saudi Aramco. IRGC has zero interest in MBS or inner Saudi politics as they see them as nothing but an extended arm of the American CIA in the region. Saudi Arabia post ottoman age did not even live for 2 full decades as an independent country. As soon as oil was discovered, the west got in with the installation of a puppet regime in Riyadh in the 1930s. They have always been CIA puppets, before the revolution from Mosadegh's crisis Shahi Iran was the same. Whenever the US wants to do something in the Islamic world they use the Saudi puppet to gain legitimacy. They want Zion Israel to be accepted post-Palestinian "problem" removal? no problem (P)GCC will lick Zioni balls first in name of "an alliance against Iran" so the rest of the Islamic world can follow. Iran and Saudi Arabia have zero issues between them from the country to the country level. As a matter of fact, Iran has fought against Ottoman Turkey, and Czar Russia for centuries but it has never fought against Peninsula in the last 1000+ years. The real reason behind rivalry is that post-revolution we could see the US in the Peninsula in form of the ruling family and the petrodollar is literally there as a target with its core in the desert, terminals, and in the sea from where it flows out. One of the reasons behind Iran putting extra efforts into creating an extremely accurate or efficient BM/CM/UCAV arsenal above its airforce is that in case of conflict we will ruin the petrodollar with these strikes. This is why you have never or will never see Saudis making much noise over us openly attacking their land. They know we got American neck clenched on their desert-like no one ever has. Not even USSR or China.
Btw we are not against the people of Arabia. We have lived side by side forever since we existed like Anatolia, Russia or Indics to east. Our problems with them start with and end with the ruling puppets.