Most of the fish you will be targeting, when deepwater jigging will attack the jig from the head first, so that's why the hook is at the head.
You can put two hooks on the rig if you like, one long and one short, but it will be more prone to snagging on the bottom and will be a lot more dangerous when landing the fish and trying to get the hook out. Amberjack are good, when they come into the boat they are normally pretty calm and just wait for you to take the hook out, Kingfish on the other hand go mental on try to wreck the boat and the extra hook can get dangerous.