The battle system is Gauntlet is based off of the one in Brawl. At its core, the same systems and factors still apply, such as dragon types. Different dragons have different types and qualities in Gauntlet, which are indicated by their type icon. These icons will show on their card or next to their health bar during a match.
 
Red Icon: Furious Dragons have better attacks.
Green Icon: Protector Dragons have better defense.
Purple Icon: Cunning Dragons have better special attacks.
Blue Icon: Swift Dragons have better speed.
 
Swift dragons being the fastest dragons, their turn comes along a lot faster than other dragons due to their higher speed stat. If your opponents have some of these dragons in their team, they will have more turns. Similarly, if you have some of these dragons in your team, you get to take more actions!