If Khamenei is "removed", Iran collapses like a Jenga tower. Or as I like to call it a "Jendeh" tower...

Iran's top leadership is not made of individual thinkers, or people with initiave, certainly no one has courage, or is a born leader. It is filled with weak Yes men, who only have the authority to enforce their positions, because Khamenei raffle ticket gave it to them.

Once Khamenei is "out of the picture" there's no one to authorize the top leadership, and they will have to choose to stay and fight, or as their character (or lack thereof) has amply demonstrated in the past, take their money and run for the contingency secret havens they have no doubt set up.

But as long as Khamenei is "still kicking" they are forced to stay and (pretend to) fight alongside for fear of retribution, if they even think of attempting to panic and flee. With Khamenei "Gone" however, there will be no one to come after them, and they can take off immediately.

That's why the key linch pin and the fat finger in the dike is Khamenei. "Pull that finger" and everyone in the top echelons of Khamenei's false house of cards, falls.

Theoretically speaking, of course...