I’m not sure if I’m misunderstanding or what but at least in my experience they Rock Golem does not collect flint or metal from rock and metal nodes. This was disappointing to me. On the other hand they are still good because they can dual harvest both wood and stone unlike the doed. Though I would prefer if they had the weight bonus which they do not
Rock elementals are extremely tough to kill or knockout. Over encumbering them inside or around your base and setting them to aggressive allows them to defend your base with their rock throw attack without being kited away by enemies.