Thank you all for the thoughtful remarks and comments. I found both DSST Org Beh and DSST HRM to have some overlap with each other (also with Prin of Mgt and Prin of Sup). HGD had overlap from Intro to Psych and Intro to Soc, just like some have said on this forum. I used the practice exams for the Petersons DSST Org Beh and HRM, and I used the REA book for HGD. I probably won't attempt to take 3 tests again anytime in the near future as my head hurts because I am trying to complete my Bachelors and I studied for and just took the Fire Marshall (FDNY) exam and I am still studying for Fire Lieutenant (FDNY), plus I just became a father. I think I have a full plate.

P.S. This site is a godsend.

Eric