You're right. This build is unworkable as I envisioned.
What about IH for heroes? I've been trying out IH on my hero. Compared to Dark Fury, heroes spend ~4 seconds every ~60 instead of 1.5 every ~6. It seems to work very well, so far:
Between Armor of Unfeeling and the spirit heroes' tendency to hang back, IH will probably survive.
The real question is whether a communing bar with no elite adds more than a time-strapped necro can. Also, you might want to put something spammy in that bar so that the hero has something to do with all the time you've saved.
If no one in your party carries SY! you can offer to go IH+SY, but I'd suggest letting a Mesmer bring Soothing Images or a Rit Soothing, if the mobs are adren-dependent.
Why bring Soothing (Images)? It's not like anything in PvE with adrenaline is that threatening. The worse that could happen is if Quetzal Tengus use Tengu's Mimicry on you, but then it's your fault for using SY! while you have that effect on you.
Unfortunatly, Turret Rangers are pretty much dead now, thank's to Anet not being able to split skills correctly. Any builds have been severely hampered.
Though PBS/ZS + Glass Arrows still interests me somewhat.