In other terms, you have no grounds to assume they are inefficient.
It's merely a US claim that no American troops were killed. Washington could be lying just as they did according to you with Iran Air 655. Indeed several suspicious coincidental deaths of US troops serving abroad were published in the news shortly after the strikes. Also Iran's intention in these strikes was not to eliminate as many occupation forces as possible, but to knock down the illusion of US invincibility and invulnerability by demonstrating the precision of Iranian ballistic missiles.
One can impossibly infer wholesome unpreparedness of the Iranian military based on a single incident. But even so, problems like this do not equal incapability to fight back effectively. As a matter of fact, the missile attack on Ayn Al-Assad was succesfully conducted in spite of the incident with the Ukrainian airliner. So the latter incident by no means implies Iran will be unable to hit US assets.
And you think Iran is not going to strike back in case its nuclear infrastructure is subjected to large scale bombing? Iran's aptness to do so was proven in the Abqaiq and Ayn Al-Assad operations.
Fair enough (and true, I believe), but then there's this:
November 21, 2008 12:20 AM
CIA faulted in shooting down of missionary plane
The CIA obstructed inquiries into its role in the shooting down of an aircraft carrying a family of U.S. missionaries in Peru in 2001, the agency's inspector general has concluded.
www.reuters.com
There are also reports that French fighter aircraft mistakenly downed an Italian airliner in 1980, with NATO subsequently trying to cover up the truth:
According to Italian media reports, confidential documents found in the archives of the Libyan secret service after the fall of Tripoli, which are now in the hands of Human Rights Watch,
www.independent.com.mt
Twenty-six years after an Itavia Airlines DC-9 crashed killing all 81 people on board, relatives of the victims have fresh hope of discovering the cause of the tragedy, writes Barbara McMahon.
www.theguardian.com
We recall Pakistan's preparedness during the February 2019 aerial skirmish against India, yet sadly Pakistan too is on the list of countries which shot down a passenger plane.
www.nytimes.com
I won't enumerate the multiple downings of civilian aircraft over the USSR and Warsaw Pact countries during the Cold War. The fact is that no serious observer would have taken these events as a justification for considering that the Eastern Bloc was unable to fight a war against NATO.
In conclusion, the unfortunate case of the Ukrainian passenger plane does not signify incapacity on Iran's part to strike back at US forces in the event of a military aggression by the latter.
As for puny Isra"el", please... Let's not go there.