Excellent Piece of Naval Analysis From Larry.

The issue is covered really well. 

It looks like the United States, along with 9 allies — Great Britain, Italy, Bahrain, Canada, France, the Netherlands, Norway, Seychelles and Spain — are on the verge of entangling itself in a new Middle East quagmire as an international armada assembles in the international waters around Yemen. The mission? Stop Yemen from threatening cargo and oil tankers headed to Israel. Tiny Yemen has surprised the West with its tenacity and ferocity in attacking ships trying to ferry containers and fuel to Israel. Yes, this is a violation of international law and the West is fully justified in trying to thwart Yemen. On paper it would appear that Yemen is outnumbered and seriously outgunned. A sure loser? Not so fast. The U.S. Navy, which constitutes the majority of the fleet sailing against Yemen, has some real vulnerabilities that will limit its actions.Before explaining the risks, you must understand that the U.S. Navy is configured currently as a “Forward-Based Navy” and is not an “Expeditionary Navy.”

The logic of Salvo Model and the issue of a leaker are well known to Houthis. I am sure Iranians did their due diligence in educating them that in the real missile exchange it is not that difficult to reach saturation threshold for enemy's air defense. You saturate it with cheap drones and low-cost subsonic missiles and you count. Same way as Dirty Harry Callahan did counting rounds. Or, if Houthis feel lucky and get the series of coordinated salvos, then they can hit opponents' ship even without those ships running out of SM-6s. So, there you go. Recall late brilliant great Captain Wayne Hughes:

Read the full title of the book and keep in mind--all of it has been predicted and these are just Houthies.