So after tirelessly working on this low poly model, I finally finished rigging, and I thought everything was ready to export. When I tried importing it along with the skeleton & materials, I get an error message telling me there's missing bones. With a little searching, I found out that it's because there's no root bone assigned to each bone. An example showed that you should select two at a time (first the child, then secondly the parent/root bone) and connect it that way. However I'm not sure what to connect where, or what the best way to do this is. I would greatly appreciate it if any of you with experience with this could help me finish this model.
(Image linked shows my rig setup, what my idea was is if somebody could guide me on which bones to connect where):