Given enough phys res (45-50), Ravager can indeed be killed without pharma with sigil and the likes. I did it on my “classic” dark one setup. And it seems my issues were the same as yours: very low OA and CC res. I’ve fixed my OA in the mean time though.
edit: good idea to provide new players with gearing hints, like how to build a full set quickly, with just a blue print as starting point.