Synthesis 
The text on the four (or five?) kinds of overseas Vietnamese is a rash over-simplification, and appaers to be unpublished synthesis.  It ignores Vietnamese living in Cambodia and Laos, or those who emigrate to be reunited with an earlier "category" of Vietnamese.  I would remove the paragraph, or rewrite it to describe the various reasons why Vietnamese have emigrated, but I would not want VNese pigeon-holed like this.