Port defense and engineer brigade

[GAGA Extrem]

The game will sum up all similiar modifiers and then divide them by the number of brigades to average the value for the whole division.

E.g.:
10% fort attack + 20% fort attack + 0% fort attack = 30% / 3 brigades = 10% fort attack
50% woods defence + 20% woods defence + 0% woods defence + 0% woods defence = 80% / 4 brigades = 20% wood defence
20% fort attack + 20% fort attack - 40% fort attack + 0% fort attack = 0% / 4 brigades = 0% fort attack