Proposed Canon
Tar Zhay is an inscrutable jungle empire.
It is said, that the ruler of Tar Zhay is incapacitated, and the side is governed by a ruling council of commander units called kommissars. It seems that these kommissars are not required to stay in their capital or in their side's territory as Jintao stays in Magic Kingdom and does mercenary work. However Jintao is technically barbarian.
As Jintato visits his capital frequently, retains his kommissar status and his side had no apparent reason to release him (Tar Zhay is described as healthy and successful), but he is allowed to hire out and they cover his upkeep when necessary, it is heavily implied he functions as a spy for Tar Zhay.