Jumbo had thicker armor on the front than Tiger and Panther, so it "could" take more hits, and it was also angled for even better incoming-round deflection. I think its surviveability and where it fits in with whichever army's tanks that define its "class". If the Pershing was the "heaviest" tank that the US had in WW2 then it should be considered "Heavy", and because of the Jumbo's increased armor and weight (it was as heavy as the Pershing). If a regular ronson is considered medium, than the Jumbo has to be considered heavy... you only get 3 options