Survivability for my heavy armor shieldless ships hinges on being able to use PD and flaks more than having extra thicc armor. If you're facing a HIL then you're in the wrong place, anyhow.
But yes, in a maxed build with skill EMP resist and the hullmod you may be better off trying to maintain high flux and having Shield Shunt give an armor bonus. For general utility, less so.
Yes, PD is good too, and ships that can use it should get it. HIL is a weakness, and not much can be done about that other than kill the beamer immediately. HIL is not too common; I tend to see those in Indie deserter bounties.
The problem with high flux is the AI enters that infamous cowardly loop running away for too long to reach a safe place to vent (then die when they fail because the enemy kept up) because it is too busy cowering away from the enemy.
I am not trying to use Shield Shunt on the flagship. This is for AI ships, especially those that like to cower anytime they get high flux fast.
After playing around with more shieldless ships (with Shield Shunt) in a fight, I noticed the following:
* Polarized Armor is a must. It helps them stay alive longer.
* Ships will die. Hull Restoration is a must to prevent most d-mods if I want to keep the fleet pristine.