This is what I was thinking, if certain weather effects and terrain types would give advantage/disadvantage to defending/attacking realm.
For example, sandstorm would give the dessert realm a bonus of 5% evade and the attacking realm would get -5% hit chance bonus. Or in green realm fights on some specific parts of green realm would give greens morale boost and other realms morale deficit. Etc, hope you get the point. I wanted to write so much more here but I don't know how =/