Spice is the season's ranking resource, contested in Spice Wars - two rounds a week, typically mid-week and weekend. You don't need to win the whole war to profit from one: destroying an opponent's secondary buildings (5% each) and then their Alliance Center (10%) lets you steal Spice even from a losing fight, up to a 30% cap.
Save Desert Protectors for decisive fights rather than spending them early - they're far more valuable when a Spice War is genuinely on the line. Building an Oasis also unlocks Desert Artifact digging (levels 1-6) across cities and villages, a steady side source of value worth assigning to less combat-focused members.
The season builds toward a Week 7 Faction Duel - start preparing battle plans well before that week arrives rather than scrambling at the last minute.