Wagner originally created and wrote the series in Starlord - after it had transferred over to 2000AD, Wagner and Grant began their writing partnership (note the last word - not 'assisting') that included SD. Rule of thumb was that whoever typed up the script was the one to recieve the writing credit. When they split up after completing the Dredd mega-epic Oz, Grant stayed on as series writer up until the death of Johnny Alpha, and thus the end of the story (or at least it should have been...)
