fanaticism and losing Cavalry Charge bonus

[Jagger]

Fire Modifiers
Enfiladed: the increase in effect of fire directed against a target unit which is not facing the firing unit.
Cavalry: the increase in effect of fire directed against mounted cavalry.
Fanaticism Value: the increase in Morale that certain specified units receive.

Somehow I missed this.  So basically fanaticism is a +morale modifier which only applies to firepower morale checks.

I wonder if it is possible to give a negative fanaticism modifier for units especially vulnerable to firepower.