Complex sentence: The unification of the empire under the draconian Qin dynasty and the succeeding Han dynasty still left salt production and distribution to merchants and local rulers whose profits rivaled the central government's own treasury in size and also took salt workers off the tax rolls.
Split into simpler sentences: The unification of the empire under the draconian Qin dynasty and the succeeding Han dynasty still left salt production and distribution to merchants and local rulers. The profits of these private entrepreneurs rivaled the central government's own treasury in size and took salt workers off the tax rolls.