I'm very confused by what you are saying, but I think I get most of it.
DO NOT connect the Arise supply outputs to a distribution block. Not only is there no reason to, but you will shot the supply if you connect the negative output to ground. Connect the outputs of the Arise supply directly to the computer only.
In electrical circuits, three different terms can be used for voltage:
Refers to a voltage above ground.
Refers to a voltage below ground. For example, the -5V output from the Arise supply is 5 volts below ground. So you can see why you can't connect it to ground.
The point of 0 volts, between positive and negative.