First I tested Guardians of Empyrion damage on my old custom Vitality RE/GoE Oppressor:
As you can see despite all the extra mods and extra summons GoE do pretty tame damage in isolation. It’s especially noticable when I attempt dummy with RE at 1:35.
Then I tested top20 Demonslayer Reaper a build with loaded Blade Spirits with extra summon:
Build
Dummy Test
Spirits damage also feels low here in isolation. At 1:09 I attempt dummy with PB as well and it’s night and day.
Conclusion
It’s worth mentioning that in-game overall damage will be better because of Necromancer’s RR that doesn’t work on dummies. However relative to full build’s damage it’s still going to be pretty small for the investment. And this is on two builds with super juiced up GoE/BS. Some Nightblades that take unmodded BS just for bit of extra aoe will be especially gutted by this nerf. As for GoE those were pretty bad as long as I remember, not even sure what triggered their nerf (top20 had one build with extra GoE summons but it clearly wasn’t the GoE that made it strong).