Honestly how many games have people lost vs Cahir since homecoming? I've had an opponent boost deck with Calveit since then and I try to optimize it every time there is an update, just cause I find it fun to play, but it never got that good (maybe I just didn't do it right). Non immune Cahir gets easily disabled, either removed, moved, locked, tall unit removal, reset... At the beginning of homecoming, he was always scorched or igni-ed. Now Yrden. He was good with regis draining boosts, who now is nerfed on order, and also on melee row so sensible to yrden...
If you let him untouched or immune and you have a boost deck, yeah, you're f***ed but that happens with a lot of cards.
I guess my point is he is not that used, and is one of the few fun option if you want to play Nilfgaard in an "original" way (not full locks/seize/tactics).
My other point is: if one person manages to get him to work, like other very rarely used cards, let him have some good times before it becomes a net deck that everybody copies (when it actually becomes annoying) until it's nerfed to oblivion XD