The design of the current Han farmstead appears to be based on the models of the pigsty/toilet, i.e. a place to dump waste, not to store food. A design based on the granary or perhaps the mill would probably be more appropiate.
It's clear the Han had a great variety of tall, free-standing towers. This is something where China differs from the Mediterranean. To reflect that, it would by nice if the Han could have (at least) three towers:
a two-storey tower in the village phase, costing 100 wood;
a three-storey tower in the town phase, costing 200 wood;
a four-storey tower in the city phase, costing 300 wood.
As pointed out earlier, having rammed-earth walls is a sine qua non. To give a better idea how I think they ought to look like in game, I made a crude drawing of cross-sections of 0 A.D. wall segments:
From left to right (red are proposed, blue existing walls):
A Chinese wall with a width at base of 20, a width at top of 12, and a height of 15; because its massive size dwarfs the walls of other civs, it's probably better to reserve this for the city phase.
A Chinese wall with a width at the base of 15.333, a width at top of 8, and a height of 10; this has a similar height to the city walls of other civs, and is therefore suitable for the town phase.
A Chinese wall with a width at the base of 6.667, a width at the top of 4, and a height of 5; a small version for the village phase.
The current Han China wall, which has a width of 7 and a height of 10; ought to be deprecated.
The current Carthaginian wall, which has a width of 7 and a height of 12, is currently the largest wall in the public mod.
The current Macedonian wall, which has a width of 5 and a height of 11.5, is probably the most typical wall size.
The current Roman siege wall, which has a width of 4 and a height of 5.7, is the smallest full-length wall.
The widths are the <Obstruction> depths, the heights the <TurretPoints> <Y> position, i.e. the offset at which units on the walls are placed, thus without battlements, roofs, etc. (The normalized cross-section volumes are, respectively, 240, 116.7, 26.7, 70, 84, 57.5, 22.8.)