Yes, in addition to Agent Alshire, there have been others from your reality, including an associate and a subordinate of yours that were recently returned to their worlds.

But, yes. Every Area has their own force in one way or another, with DATS being the main entity that employs Tamers in that capacity. We act under the authority of TigerVespamon's Royal Base, which is allowed jurisdiction in many areas of the Digital World, save a few.