DEV_Domain > Itself refer to one env <Dev>
TEST_Domain> Itself refer to one env <Test>
As per standard naming convention, I consider them different. so if those are different you should create 2 different domains one for Dev and one for Test with a similar setup.
Dev could be single instance setup, but Test witll be just equivalent to PROD / clustered setup.
Keep artifacts in such manner that domain name, managed server are having same naming conventions across all envs.
This will help you to move from test to prod easily, and every new deployment will have the same steps without making any change to config steps. you can test the stuff easily and compare will be easy too during fixing issues.