Global makes very good points. Liners are furnished with the most high tech luxury equipment for the queen, VIPs and rich people, or high tech security systems for prison liners. They are made for hauling people, not Diamonds or Military vehicles.
The furnishings should reduce the size of the cargo hold. Maybe 3500 max, but certainly no more. How they are now can stay as long as they have less cargo. Otherwise it is unbalanced, and we will whore gunboats to kill the liners coming through trading.