Half siblings definitely looks like a good possibility--the cousins look like cousins, the aunt looks like an aunt, and the suspected half sibling looks like a half sibling--all of those people came up in the range you'd expect to see.
Network President Jenny LeFevre, Agent Orange Victims and Widows Support Network, attributes more than 250,000 deaths to Agent Orange, a toxic herbicide the U.S. military sprayed over Vietnam from 1962 to 1971.
Eligibility - Service in Vietnam or Korea. VA presumes that Veterans were exposed to Agent Orange or other herbicides if they served: In Vietnam anytime between January 9, 1962 and May 7, 1975, including brief visits ashore or service aboard a ship that operated on the inland waterways of Vietnam.