For example, under the Walls tab I have merged enough lower level walls to get 4 Crimson Alloy rooms. But I can’t use them. There is no way to replace my Night Iron walls with the Crimson Alloy.
I can’t replace my Crystal Room with the Ruby room.
Under the Rooms tab, I can’t use the 2 Arcane Shield II wizards I have. Nor can I deploy the 2 Elite Garrisons I have.
Under Weapons, I can’t use deploy the Peregrine, Branta, Ossifrage, or Albatross.
The battles I have been winning against other players who have those better shields, walls, and weapons has been through luck.