I have no love for bad documentation. Thanks for the help!
Instead of simply going from D2 tot 3 to 4 etc. I now use a lookup table (array) with the last four pins as A0-A4). Easy hack in this code, just add 1 to the index instead of the pin number when in a loop.
Now I can get all drives to work, although there is still an annoying issue with drive 8..I'll get that fixed soon enough!