The booty not necessarily to be divided into five equal parts. One part is going to be given to Allah swt, the messenger sas, the near relatives, and the poor. The other four parts will be distributed among the soldiers. One part will go to those soldiers who went on foot. Three parts will be divided amongst those soldiers who took their own mounts to the battle [they are sacrificing more than the others, i.e. camels, horses must be trained and are used for daily chores as well, they must be fed and maintained]