This match is much like the previous quest; you are facing four versions of the Sultan, but three things are different from the Rat fight. First, you have no arable land (not that much different); two, you are utterly surrounded on all sides by them; three, you each start with 10,000gp. We can make some cheese happen with this.
There are two ways to play this map: you can play it out the long and drawn out way as it was likely intended, or you can rush them all for an easy win (which I did). First I will write a "Legit Strategy" (which is merely conjecture as I didn't actually play it that way) but you can skip to the bottom for the "Cheese Strategy".
--LEGITIMATE STRATEGY--
Note: I did not bother to try to complete the game in this manner so the tactics presented therin; while theoretically solid, you may have to change one or more elements as developments demand. If you find my tactics do not work, please find out for yourself a better way and replace this section with your experience.
Our biggest problems are the fact that we have to defend ourselves against four people totally surrounding us, and the fact that the only things we have to work with are wood and stone. There is iron on the map but it is all squarely under the grip of one Sultan or another. We start with a huge pile of cash, but so do they, and with their tightened grip on all the iron we're going to have to cause them constant damage with low-investment if we're going to drain them. We'll also need to pay more attention to our defenses than we did with the Rats, as Sultan uses slaves as well as sturdy arabian swordsmen that will prove more challenging to deal with.
After of course placing a market, stockpile pieces, and granary, the first thing I recommend is to place one tower square or round facing each Sultan, close enough to each opponent that a mangonel can hit their infrastructure. You want to enclose your keep with at least a thin wall of stone with a singular internal staircase. Make sure to fully enclose the stone to your southwest. This may be difficult to place if SUltan's troops get too close; do this side first and fast. Make sure you Buy in at least 35 bows. Place an Engineer's Guild; our plan is to put two engineers per tower onto a mangonel set to shell their walls, gates, and important buildings at all times. We also want minimum ten archers per tower to cover the mangonels and to protect against invasion. You can probably wait to enclose your keep until you get stone, but in that case you'll need to place a single brick of wall and stairs at each tower.
With your defenses set for now, let's talk food. This one is going to be a doozy. You will need to buy in food or its alternative constantly and there are a few ways to do it, as I described in the last walkthrough versus the Rats. First option is to buy in all four food groups and keep your rations set to half; this will even out with no taxes at stable popularity. Second option is to buy in wheat and built mills and bakeries; this is cheaper overall than bread itself (in fact the math shows you can even turn a profit from bread) but this requires wood investment and more villagers eating more food. If you're only placing a couple hovels maybe this route isn't for you. Third option is to buy in hops and build breweries and inns, to supplement or replace the prior two options. No matter what you do, keep an eye on it constantly and keep buying in what you need.
Now for economy. All we have for now is wood and stone; we're going to need to turn our wood into a higher form if we plan to make money off of it. Build several fletchers, set to both bows and crossbows. We're going to need a lot of both to defend ourselves and we can sell the rest for more than raw wood. Crossbows do sell for more, but they may take more time or wood than bows to produce, I'm not sure. You may also place poleturners for pikes, but I wouldn't. Place as many quarries as you can squeeze and sufficient ox tethers to carry in stone as fast as you produce it.
Once you've gotten some resources going, it's time to shore up our defenses and breathe a little easier. Buy in leather so you can produce crossbowmen and archers from your fletchers; the crossbowmen are going to help a LOT when it comes to arabian swordsmen rushes. You may also want to place a mercenary post and build slingers in case swordsmen breach your walls - they have too short range to fight bowmen but a swarm of them can cut down swordsmen quite easily. Once you have stone that you don't need to sell, I recommend placing more towers, and more mangonels (maybe even ballista) to harass your enemies and destroy their buildings and economy. Build a couple gatehouses so you can come and go and decide on who you want to hit first, and how.
My instinct would be to attack the southwestern Sultan first, but if you look at his land he doesn't have a pot to piss in; besides wood and bumming other people's stone and iron he has no good land for you to gain. In fact, by now you've probably run the bastard completely dry, so ignore him for now. Our easiest target to hit - and the most dangerous to our stone operation, is the southeast Sultan. By destroying him we finally get access to iron as well, which for most playstyles helps a lot.
My personal approach would be for mangonels and trebuchets right outside to hit his gatehouses or towers as I buy in maces and leather and swarm with macemen to take him out. Many strategies would work against the Sultan, just keep in mind that his positive fear factor will make his troops tougher than the average warriors, so bring more than you might think you need. Once he is dead, place a standing force of archers, crossbows, and fire ballista to guard your new land, place iron mines for iron selling or making weapons, continue placing mangonel towers and trebuchets to destroy their economies, and take them out at your leisure. Good luck!
--CHEESE STRATEGY--
Set game speed to 20 and prepare to move fast for best results. After I placed Trading Post, expanded Stockpile, and Granary, I placed half a dozen hovels, two armories, barracks, bought in 50 maces and leather, and started producing macemen as fast as I could. I placed six water pots so I could have more than 24 villagers in reserve if I left it alone for a while, resting them all as I needed troops. I kept buying maces and leather as they were used, and as soon as I had 50 macemen I sent them at the southwest Sultan directly, set to aggressive stance. As I was waiting on this, I turned my waterpots back on (so I had a maximum pool of 42 villagers instead of 24), sold all my stone, iron, wood, pitch, wheat, what have you. Literally everything but bread was sold, and I bought in a bit of every other group to keep myself at 100 popularity. I kept building macemen and as the first Sultan died, I only lost about a dozen macemen. I sent my remaining force at the southeast Sultan, and right as my previous force passed my barracks I sent as many reinforcements as I could muster along as well.
Once you get around 1-3000 you want to be careful so you don't unwisely spend money. Start buying maces and leather in small quantities, 5-10 apiece, and field them in small groups as well. I don't want you to have 50 maces, 10 leather, and no money to make more guys. Once the southeast Sultan drops, brings your guys back to link up with your fresh troops and send them all northeast. Use the gold stolen from the vanquished to buy more maces and leather and keep pumping out troops. By the time you kill the third the last Sultan will have enclosed himself and this is where I got worried, but as long as you have more than 100 macemen (which I did and you should) you should be able to destroy one of his sentry towers, swoop in and murder the last.