I think there should be some option on the selection screen to customise your CJ in size, or just pick a CJ which suits your playing style. For example a muscular CJ could have a more higher chance of not dieing then a skinny CJ, which would mean the muscular CJ would take longer to kill then a skinny CJ due to the persons built and size etc.
Also, like in 0.5, the sailor can regain health, i think that possibly that could be added also to each character at different speeds. Obviously the fat CJ would take longer to regain then the rest etc.
Basically size dosent matter