I meant why wouldn't they have made a clone ages ago.
This ruler we have is super, let's make a clone now, freeze it. If they get assassinated we just wake up the copy and keep on truckin'.
There would be about 50 Rodens, Heth's, Midular's etc in a freezer somewhere waiting to be woken up.
Memories wouldn't be current but you'd get your precious rulers back asap.