Tactics for the Swamp (Fortress).

For the Swamp faction, this is an ideal combination. Fire is not needed at all, as some of the spells that are required are also available in Water Magic. For example, Bloodlust is equivalent to Blessing, and Curse is equivalent to Weakness.
Air is also not necessary. Of course, Expert Acceleration is great in itself, but if it's not available, it's not critical.