Just courts have a variable effect on morale as well. For these options, it seems like there is one primary variable that has a predictable result, which would be the raised variable that Foundation mentioned. Of the two remaining, the court options generally affect one negatively and one variably. Just courts are probably the exception.
Mercy: Raise morale, Lower control, Variable loyalty(?)
Just: Raise loyalty, Variable morale, Unaffected control (??)
Harsh: Raise control, Lower morale, Variable loyalty