Implementing a true turn-based would be an enormous job and not likely to be feasible in this timeframe. My guess is you have the option for a streamlined system where you really only have to control the main character and the DK is primarily AI controlled.
In this timeframe, making a decent AI for the DK is at least as unfeasable as adding turn based combat IMO.
My guess is that the extra combat modes, will be added in a patch to the German version.
