To maximize replayability, Defending the Malay Barrier (The ABDA Campaign) includes three historical options to begin the campaign - the historical result of the Force Z sortie; no Force Z sortie; or to play a turn that includes the Force Z sortie. The campaign also includes four options for the Dutch Order of Battle - historical; the addition of HMS Tiger as HrMs Tiger based on the article "A Dutch What-if" by Jim O'Neil from the Royal Netherlands Navy supplement; the addition of two of the "Gneisenau-type" BCs from the Dutch "Project 1047"; and a combination of HrMs Tiger and one "Gneisenau-type" BC from the Dutch "Project 1047". The latter three include corresponding additions to the IJN Order of Battle.
Attached are the ship logs for another Dutch OB Campaign Option for Defending the Malay Barrier. In this case, the Dutch obtain the rights to the uncompleted German Mackensen class BCs:
Based on the disarmament and military restrictions from the Treaty of Versailles (and also just for spite), the French object to the whole deal, and especially the Germans building the planned 35cm (13.8") main guns, so surplus British 13.5" guns are purchased (probably with a kickback to the French). Coal-fired boilers are removed, they are converted entirely to more modern oil-fired boilers. Two casemate-mounted 5.9" guns are removed to save weight, leaving 12 (Dutch) 5.9" guns. The 8x 8.8cm L/45 FlaK guns are replaced by standard Dutch 4.7". Torpedo facilities are removed to save weight. Boat facilities moved slightly aft, a double-ended catapult is added between the stacks, though there is no room for a hangar. 2 floatplanes are carried.
The above narrative assumptions allow the Mackensen class BCs to be included in the campaign with a minimum of fuss - e.g. they can simply use the GQ3 Royal Netherlands Navy Gunfire CRT. Use them in the same manner as HrMs Tiger or two of the "Gneisenau-type" BCs from the Dutch "Project 1047" - i.e. with the same corresponding additions to the IJN Order of Battle.