You need to change your strategy? No problem Commander! For a faster change in army set-up, save your favorite troop loadouts and swap all troops in one go!
The feature unlocks at Gunboat level 10. Access it by tapping your Gunboat, and selecting the blue troop icon. Gunboat level 10 carries two slots, with additional slots unlocking at Gunboats 13, 16, 19 and 21.