In the left image, you have the pod, Bob, in the lower left corner a 5*1 cube meter box and the 3 other cubes for the cargo hold. The 5*1 box represent the drone bay space, equivalent to 1 small drone, of 5 cube meters.
The cargo hold of the Tristan is of 140 cube meter. To get the accurate size, I made one 5*5*5 cube, one 2*2*2 cube and another 2*2*2 cube minus a 1 cube meter. This totals, 125 + 8 + 7, 140 cube meter.
My conclusion is that the cargo hold and drone bay of the Tristan is of acceptable in size.
;)