size 4+ tramplers dont work Ask my friend that Used earth elementals against 25+ defence guys.
MInd burn is a good point actually that is the only reliable way (sort off hard to pull off against 17 MR but might work).(and even then its hard if he adds the amulets but I guess early on might work).
Mind hunt was the non battlefield way to kill them I guess.
Horrors will die quicker than they can kill/route the commander.
Vine arrow try hitting through storm/ mist (and they have arrow fend(not sure if it stops the vine arrow have to check ).
Earth meld spam has range issues as well. 25 range is not reliable.
I agree abut the fear point but not call horror maybe something like massed fear generating effects. Sidhe lords do have low moral I guess. (kind off unthematic since they are supposed to be brave heroes

and poets but I guess they rely mostly on the poet part)
So basically if you have no astral against them you are screwed. Blood has life for a life but you can always always assume there is a screen of PD when he is defending.(also not sure if Mistform negates the damage)