Your face three adversaries in this mission, all Sultans, and with no allies. They all have 20,000 gold to your 7,000, but you are well supplied.
This is one of the "artificial" map layouts designed for its game play, rather than realism. It consists of nine interlocked, roundish settlement areas, three rows of three, sort of like a tic-tac-toe layout. Each enclave is connected by an opening to its two neighbors, and a long canyon to the central oasis, sort of a spoke design. The central area is a lush oasis containing the only farmable land and lots of trees. The surrounding rock areas that create the layout of the map are all high terrain resulting in the useable areas being bounded and shaped by high, sheer cliffs.
You're in the upper left, northwest enclave, with Sultan "The Wise" to the south. To the east is an unoccupied area, and further east beyond that in the northeast corner enclave, Sultan "The Kind". Sultan "The Just" is much further removed in the southern central area.
The Sultans are a moderately difficult foe with a good variety of troops: catapults, fire ballistae, Arabian bows and swordsmen, slaves, fire throwers, and assassins. You'll be defending on three fronts, the most immediate on the south because of the proximity of Sultan "The Wise". Special care must be taken in this mission to prevent assassins from running amok. Moats are a great help in this respect.
Information source: https://stronghold.heavengames.com/downloads/showfile.php?fileid=2045