Do game mode mods like Secret Society need to be separate?

[Brixter]

Some of my mods are related to the game modes. For example:

If I add an ability to all Melee units, then it should affect Vampires and Hercules, etc.
If I modify fort improvements, then it should affect Vampire Castles.

Will it cause problems if my mods affect Vampires and Hercules when my game has Secret Society and Heroes disabled? Or should I keep them in a separate mod in case I don't play that game mode?