"Retrofitted Hangar Bay" gives you the equivalent of additional Encumbrance Capacity based upon the size of the ship.
"Smuggling Compartments" converts a fixed amount of existing Encumbrance Capacity.
Shouldn't it add a new amount of Encumbrance Capacity directly tied to the size of the ship?
For a Silhouette 6 ship, 25 encumbrace of hidden cargo is absolutely nothing...