The only problem with the scenarios you presented, based on what I’ve seen on other threads, is that Saudi Arabia is pretty much incapable of projecting military force. Apparently they deliberately keep their military in a poor state of readiness because a military coup is a much bigger threat to their leadership than Iran is.
I’ve have seen that opinion as well. I question with the air and naval assets they own why they would not have offensive power, but I haven’t got another source, at least on the weekend, to understand this better. I would concur that in many cases these regimes have military mostly to keep their own people in order. In that may be the answer. If you have a weapons platform but you never train with it to do anything but suppress your own people, then they may not have a viable offensive force.
Though this was not addressed to me I beg your indulgence for my reply. The Saudi population is a pampered population. Their military consists almost exclusively of their well equipped Air Force. Their standing Army is a joke. Nearly non-existent.
For this reason they are ill prepared for a serious war. The rag tag Houthi rebels in Yemen are giving them a serious problem because of this fact.
The thing that has protected them from Islamist invasion and destruction is the fact that the most holy of muslim holy sites reside in Saudi Arabia and they do not want to desecrate those sites.