Applejack and Groudon look a lot alike, both are terrestrial and have several things in common.  
And I think they’re both used to getting dirty and they would love to grow crops and work in the fields.
 
Rarity and Kyogre are like reflections, they both have a lot in common. They both like to stay clean and pretty and would be afraid of getting dirty. And they would both love jewelry and other things that are pretty and shiny, go relax at the spa and have it all just in luxury. And both of them would love to make clothes and accessories in many different styles.
 
With that, Groudon as Applejack and Kyogre as Rarity would make a lot of sense. Groudon would be angry with Kyogre’s “frills” because he doesn’t like to get dirty. Seriously hilarious.