If you tick the box Inherit date, it means that the “Due date” of a child is inherited from the nearest parent. For example, if you have a block that has the due date December 12th 2018, add children to this block, and tick the box inherit date in every child, these new activities will inherit the Due date December 12th 2018 (the due date that the parent had).
Therefore, our recommendation is to decide on the due date of each parent first and then tick Inherit date in every child. Then you don´t have to figure out a good specific due date for each and every assignment.
Please note inherit date is not applicable in Promote Next Gen