That's because DD isn't a proper campagin, but just a collection of free levels (at least, it's showed like this in KeeperFX) and so it doesn't have its own campaign data, but use the data of the campaign that you're playing (continue the game shows the map of that campaign...). So you have to play the campaign that have statistic that you want for your levels, in this case you will want to play with original campaign (in fact, the DL patch) data. Ancient Keeper it's thinked to be more similar possible to the original one, and so the values are lowed to simulate the cap...