This one is going to be a doozy. You're on the classic map Last Stand, but if you think that means you'll have height advantage on your enemies you are sorely mistaken. One Caliph sits high above the world on his lofty hill (giving his notorious tower height even more range), while another is backed up by the Sultan to the northeast. You are crammed in the southeast with the Snake (an ally, for once!). To top it all off, you have 3k to their 40k. This one is going to be tricky but if you can survive the first twenty minutes you've got this.
You're going to want to zipper up with and aid the Snake immediately, since you and he's fates are intertwined. I liked my wall up with his to enclose us both within a wall, but since the high Caliph will send catapults down on you, I might recommend digging a moat with some slaves instead, and having a couple gatehouses with drawbridges. His spearmen will actually help you once his own moat is complete.
For initial defense I recommend a square tower within your own lands (out of reach of Caliph's towers) manned with 10 archers, as well as a ballista. This is my no means a wonderful defense but at 3000 gold it's the best you can do. Try to hog the starting stone and iron to the southeast, unless you trust the Snake to make better use of it than you. Now we have a pair of questions: how are we going to eat, and how are we going to make money?
Set your granary to half rations and use available farm land for wheat. Place woodcutters to clear out land, a mill and some bakeries, as well as an inn. You start with some ale and hops, so a brewery as well will ensure you have some ale for a long time. Until your population gets so high you need another inn this should allow you to keep at half rations for a good long while.
As for money, until we can afford to expand our land (some very big attacks are coming very soon) I recommend placing several fletchers, one third making bows, two thirds making crossbows. Not only will you need both units in your defense, you can sell crossbows for a high profit; do not be afraid to buy in wood and sell crossbows to keep your economy going.
It is important that you keep some gold in reserve. I recommend you field about 20 slingers to be placed at key locations, such as Snake's gatehouse or your keep. All three enemies are going to bombard you with lots of bows, horse archers, and swordsmen. As soon as you can afford it, buy in some leather and field crossbows to protect you both. If the Snake asked for your aid, you'd better help him or he WILL die and unfortunately, you need him BADLY.
Once the final panic was over, I used excess money in the following ways:
- I built more fletchers set to crossbows, and sold excess crossbows to buy wood in an expanding business generating money.
- Any stone I could afford not to sell I kept building more square towers adjacent to the first, manned with ballista (once the towers got close enough I started building mangonels to shell the high Caliph's gatehouse; before I sieged the high Caliph I probably had a dozen towers with either ballista or mangonel firing on whatever fun thing I could find)
- I kept building a force of archers and crossbowmen, sending them both to my own towers and to the Snake. I built a square tower northeast of his keep and filled it with ranged units before destroying the bottom stair step, to serve as a first line of defense against anything that tried to kill him.
- I saw that whenever the Snake place any quarries, farms, or mines north of our keep they were destroyed swiftly and brutally, but that the southeastern land was free. Once I got 20 spare archers I placed them equidistant and built quarries, ox tethers, woodcutters, and iron mines, on the southeastern land. It will take a lot of men to defend this land, but if you can it will make you a lot of money.
Keep increasing your turn out by settling more land and churning out more fletchers. Then you will have the power to do some real damage. I built some trebuchets to keep hammering the Caliph's towers and infrastructure while producing blacksmiths to produce macemen (though you'll be selling most crossbows, keep fielding crossbowmen and archers, both for yourself and the Snake). Once I had 150 macemen I blew a hole in the Caliph's wall and took a chance, and defeated him.
Once you have the ability to use the high ground, I recommend producing a large force or archers, crossbowmen, and fire ballista and sitting them there to slay any errant units of the Caliph and Sultan. If your force is large enough it will prevent any future invasions whatsoever as long as you replenish the troops every now and then. You will also be free to use all the southern rim of iron and stone for yourself, so fill 'em up. This will give you the money to do anything you wish.
Both remaining enemies likely still have 20k or more, so you'll either have to make one giant strike force or whittle away their money. For me they both took two waves of roughly 200 macemen, first to exhaust their gold reserves and then to deliver the finishing blow.