Completely agree something needs to be done to make this more fair for the smaller players without penalizing the larger players. A get solution would be making the Wizards appear randomly and adding something such as a dragon or “boss” appear during this extremely long event.
Another suggestion would simply be to make more than one room in guard the goddess, like there is for Pet Boss. Have it split up by levels, which gives incentive to keep growing as well as not hindering anyone group.