What about ten people and 100 cal.?

0 = dead - black checker piece
1-3 = dying - penny
4-7 = hungry - nickel
8-12 = healthy - dime
13-16 = fat - quarter
17+ = very fat- red checker piece

This can be done with a version of the 'coin game' coins on a checkerboard. you start with random placement of the players and set rules that you can change to reflect societal conditions. You can have cooperation where richer coins will voluntarily 'give of themselves' (make change) to help their hungry neighbors or tyranny where richer coins can take from weaker coins.

In a zero-sum checkerboard, I predict wealth hoarding to the point where a real society would devolve into violence. In a checkerboard where it is possible to add wealth into the system, I predict disparities, but high levels of survival using realistic rules.

Regarding the rules for this coin game, I would not see the utility of saying that 'any character with more than 10 cal. will give all his cal. over 10 to the poorest character' because the character would not have real world motivation to do so. In this ruleset, all characters will soon have perfectly equal cal. and this does not happen in the real world.