I confirm my theory that I couldn't stand up the wardrobe from it's side without it falling apart.
The lack of space in our bedroom meant that I built it on it's side and then tried to pick it up, unfortunately it did a parallelogram shape and then pulled all of the fixings out of the crappy chipboard.
Thankfully I did manage to restore all of the holes with the end of a screwdriver, some wood glue and a bit of care.
After installing the draws, it turned out that the door hinges had to go where the draw runners were attached so I had to move all three sets of draw runners before hanging the doors.
Anyway, it all came together in the end and looks fairly straight and true and I just need to attach it to the wall when the boss is certain which wall it will stand against.