In what order should you place your dragons on the flanks?

The two flanks (left and right) are symmetrical: what matters isn't "left vs right" but which dragons you put there and their Initiative (turn order in combat follows Initiative).

The placement logic:

• Center = aura (your spreader, Champion or Warrior).
• Flanks = your two best GREEN dragons for the troop type you chose (+20% stats).
• If a dragon lands a key debuff (lowering enemy Instinct or Initiative, for instance), make sure it's in the army — that effect helps everyone.

Don't waste a flank on a neutral or red dragon for the troop you're fielding when a green one is sitting right there. Green affinity first, raw power second.