Severe damage does not need to be just something stuck. You could have an FCU fault causing a much higher EGT on 1 side. It could be extreme vibration with all bits turning. If the engine is not surging, but it is exhibiting gross bad behaviour be suspicious about Damage. Further, I notice the new NG QRH SEV DAM conditions says abnormal indications accompanied with airframe vibration. A simple N1 or N2 = 0% seems not to qualify. Are Boeing saying that a stuck fan/turbine will cause VIB automatically? trouble is it doesn't in the sim.