Century: Age of Ashes

Pretty simple achievement, once you're in a Spoils of War match, just focus on taking down the Gold Collectors that are jotted around the map (they're marked as yellow flying around). Fly behind them and attack them to collect their gold, each one you take down should give you at the most 100 gold coins.
Repeat this process one more time till you get 200 gold coins, and then quickly make your way back to base to stash the coins, and boom easy 20 gamescore.