I agree, it's very easy to see who has a stoneskin popped in the middle of a large scale skirmish/raid.
Iron armour has a damage reduction of 60%, resistance 3 also has the same damage reduction. This means that a player with stoneskin takes over 100% damage reduction, that's insane. I understand you put your life's work into leveling alchemy and don't want your toys taken away, but come on, open your eyes. This **** is utterly broken in every way and saying 'run away lol' as a counter to it is extremely poor.