Seeing as when Valeriy (who is quite a bit taller than Gage when 'standing') joined the household Gage was only mostly intrigued because Val quickly showed signs of being submissive and skittish, I think it could go well but only if the other "animal" did not try to usurp his status as top dog… Even if the other was not agressive, if he easily subdued Gage without even trying because of being bigger, Gage would def flip out and try to kill it, which could quickly go really wrong both ways. Even with Hunter which he has a bond with him and sees as equal he would try to bite if he held him down in anyway that displayed dominance and not just the usual roughness he can have when handling him as he takes care of him, so…

Welp, def not a risk worth taking, it's probably enough of a hassle to get Gage not to try and pick up on bigger wild life so let's not bring the same chaos into the house lol