Garthanos
Arcadian Knight
Second wind is cinematic, it reduces the need for healers or clerics to be only healers, and makes hp a bit more strategic. So yes! I am fine with it being an encounter ability.
It makes more sense or as as much sense as having a healers kit able to heal an absolute truck load of hp.
I chose encounter resource because I feel its part and parcel to the heroic turn around....