I want to suggest to the devs my preferred system. It is still rough, but I think there're a lot of potentials.
Refer to the image below:
Logistic system
*All track, road and city will generate 3 logistic points.
*logistic points descend 1 by each hex.
*special/hard terrain (forest, hill, mountain, river...) will lost 1 logistic.
Supply system
*Some track/ road will have supply station from the edge of the map.
*Each track supply station will provide 10 supply points(green numbers in the image), each road supply station will provide 5 supply points.
*Some city will generate supply points as well.
Logistic zone
*In a map, normally player will have a continuous logistic zone. However, some times players may have several independent logistic zones.
*Each logistic zone will calculated independently for supply points, as a total number of all supply station and cities in that zone.
Supply consumption and penalties
*Different units will require different supply points(blue numbers in the image), normal infantry may only require 1 point, heavy tank unit will require 3 points.
*If the hex where unit locates has no logistic points, unit cannot be supplied at all (Russian infantry in the image).
*If logistic points is lower than supply requirements, unit can only be partially supplied (Russian 76.2mm gun & JS1 in the image).
*If total logistic consumption in a logistic zone is higher than total supply points of that zone, performance penalties will apply.
Food supply
*As default, all units have 3 food points.
*If units stay in the hex will any logistic points, they will not consume food points.
*If there are no logistic points, units will start to consume 1 food points per turn.
*If units run out of food, they will suffer performance penalties.
*When units run low food points come back to logistic chain, +1 food points per turn.
