I think you are underestimating it, and very likely overestimating the militaries of those Gulf States. I've seen those guys in action, and actually trained some of them back in the day. And I'll just say they don't quite have our military ethos.
The suggestion was only to hold a small area for a short time to sieze uranium, not take the whole country. It isn’t as if the Iranians have effective air defenses.
The closest of those sites is about 300 miles inside Iran, and all could be reinforced by the Iranians quickly. The Gulf States couldn't possibly fly in enough troops quickly enough to hold those places for long enough to do what is needed to be done if the Iranians wanted to stop them. It would be a disaster.
You're really overestimating the ground capabilities of the Gulf States.
You may be correct. Much depends on the ability of the Iranian command and control. It appears to be fractured.
We will see what happens.