Okay, whenever doing hard mode on Dynasty Warriors 4: Empires, always be sure you end up with a group of officers which you are comfortable with.

Also, if doing Fictional mode, your best bet to survive in this game would be to pick Luo Yang as your first territory.

This map is very easy to defend because the main stronghold is very hard to get into. There is however another map that you can pick, but it has less revenue.

Pick Nanman territory and it enables your force to use the poison swamps against the enemy.

If doing historic mode, both of these maps will already be taken, so your best bet is to pick a territory next to Nanman and attack it from there.

If you follow these instructions, and with a little bit of skill and luck, you can beat the hard mode fairly easily.