I have a singular one in a 180 gallon and LOVE HIM!
I would recommend possibly returning one of them as I feel only one would be better suited for your tank and there's the possibility of the two of them fighting as they mature.
They're great fish all around with wonderful personality! Mine eats anything I throw in the tank for the other fish (frozen of all varieties and pellets) and keeps to the sand and his burrows. He rarely ventures into the water column, so make sure you keep as much of the sand open as possible! The one I have doesn't stir up much sand (cause sand storms) either. Very pleasant fish addition to most any tank I think!