The trade exploit is dead. Long live the new economy. In Build 16843731, the best way to make money is a combination of Bounty Hunting + Caravan Escorts.
Here are some general tips to help you get started: Sands of Salzaar Build 16843731
The Witch was bugged in earlier patches (her summons would despawn randomly). In Build 16843731, she is the undisputed queen of solo play. The trade exploit is dead
You cannot solo the entire Sultanate. Your army composition matters more now than ever. The build changed how morale works. If you recruit units from too many conflicting factions (e.g., Holy Knights and Dark Mages together), your army will desert you overnight. Holy Knights and Dark Mages together)
The "Desert Storm" Composition (Recommended for all builds):