Surprise/Pinkie Pie: like firefly and rainbow , they are practically the same, except for the difference in species! Loud, happy, bouncy….although Surprise is even more inclined towards pranks, and leaves the party going to Confetti

Applejackx2: the most similar out of appearance, as they could very well be sisters. Both are strong (although I headcanon g4 applejack as being huge) and work at a farm, but G1 Applejack is much more skittish and clumsy

Sparkler/Rarity: pretty horses who love pretty things! Sparkler does take the selfishness that Rarity sometimes exhibits and ramps it up to 11, as unlike her future counterpart she doesnt have even a drop of generosity in her primped mane.