Yes, EMP weapons are great vs. robots.
But what the heck does "hardened" mean here?
A named upgrade from a normal varient.
Games do this some / most times ( Bandit "ringleaders" ), the guy who helped with the leveling was a modder and modders are crazy for this pattern.
When it comes to areas of difficulty and special loot even more so.
Beth game mods that use this are usually "overhauls", and fix many issues of gameplay not being realistic / difficult enough, and are ranked very high in favour by gamers.
So it's easy to import this system that gives some warning of what you're facing when you face it, that long running fans appreciate.
At least this is what I believe the hardened prefix means, I could be wrong on any issue I posted.