This my impression too. So basically many countries, even those as well equipped as the Saudis face a similar dilemma. The difference is, the Iranians being in the middle of a target rich region can create much more havoc than others.
Still I presume U.S. troops/engineers being sent to Saudi are going to work on anti-projectile defenses of some sort. May be expensive for the Saudis, but presumably they will ring all their vital oil installations with similar defenses as deployed by the US navy.
It's a token deployment, mostly for US domestic consumption. The consequences of a direct conflict between the US & Iran are utterly incalculable, other than the strait of Hormuz being closed to commercial shipping. The mere threat of sinking will keep them away. If it really gets ugly we're not in good shape to do much about it, either-
Iran Has Hundreds of Naval Mines. U.S. Navy Minesweepers Find Old Dishwashers and Car Parts.
As tensions heat up in the Persian Gulf, the Navy’s minesweeping fleet may once again be called into action, but its sailors say the ships are too old and broken to do the job. “We are essentially the ships that the Navy forgot.”
www.propublica.org