Lifting a 50 Kilogram bag of Wheat Grain single handedly is hard to do, even for a Guard who has been under Woldemir's training for quite a few months now. I mean a Guard can lift one and throw it on a Wagon, but it would take most of his energy. It isn't so helpful when a Guard crouches over mud and tries to regain his energy after lifting one Bag. It would be a big time waster.
So instead, it became a two man operation. Two men grab a side and lift it as they partially speed walk their way towards the Wagon, this is the best option. Weight distribution is fair, most can lift 25 Kilograms easily. Even 30 wouldn't be a problem if the two don't manage to distribute the weight properly.
