Leaders can and will be killed all the time, that is the reality of war.
1 - What needs to be fixed is that there are automatic replacements of senior leaders. Replacements should not have to be nominated by the leadership. It should be based on "automatic command authority hierarchy" ..
2 - Those replacement leaders MUST be in C&C, ie the core C&C must never be left "unmanned" from someone who can make at the moment serious executive orders with full empowerment to do so.
3 - Not have any critical "choke" points in your C&C to make decisions based on pre-greed SOPs.
For 18hrs at the start of the attack, nothing happened in Iran because leaders had to be "personally nonimnated" by the Supreme Leader. That was CRAZY INSANE ...