Their assessment seems grossly misjudged. What is true is that Iran's air defense systems are obsolete. And the Israeli air force can penetrate the Iranian air defense and neutralize it effectively. That would allow the Israeli air force the opportunity to operate unhindered above Iran and carry out multiple sorties to destroy the Iranian nuclear program.
The nuclear program is the most, and possibly the only priority target for the IAF. And even according to this report a force of 10 B-2 bombers should be enough to deal with the 5 main targets of that class. Now Israel can allocate 25 F-15I and dosess of F-16I to carry out multiple strikes against the same targets. Other targets that are of lesser important and are above ground can be dealt with by cruise missiles and drones.
Now all the calculations about the Iranian offensive capability are quite irrelevant. If Iran chooses to retaliate against the Gulf States, or if Iran chooses to block the straits of Hurmuz, or especially if Iran attacks US forces in the gulf, then They US will enter into action and destroy the Iranian air force, navy, their nuclear program (what's left of it) and their missile industry and arsenals.
If Iran limits the retaliation to Israel, then that is nothing that Israel can't deal with on its own. It may escalate to a ground war in Lebanon and to missile attack on Israeli cities. In this respect the short rage missiles of Hezbullah are more of a threat then the far fewer, and very expensive, long rage missiles in Iran that threaten Israel.
Also there is an over emphasis in this report about ballistic missile defense capability. In fact BMD is only worse the resources spent over it to counter unconventional warheads.
So the only real question is can Israel technically destroy the Iranian underground targets or render them useless for a long time. And that is one secrete that is still not a public knowledge. Israel has been working on plans to strike such target for a long time so we can make some guesses about that. Even if Israel can't destroy the most sheltered target, by destroying all the infrastructure and all the supply chain that supports them, they will become useless.