Thank you!
Just one note:
"I don't think anyone from that group can give Shingen burst, right? I can't think of any Fire Hime that does that"
Taikoubou can give +35% BG to one ally. So, technically, i could reliably use PF, but she's R. However, as you say, I'm stuck at -35% Def (without Vine) if I don't use Herc.