Pine weighs less than Whisper currently, though they're both still gaining weight and their resolve and agility CP is about the same
(Whisper: 19 agility, 17 resolve, Pine: 21 agility, 20 resolve)- though I'm unsure if this matters.
The weather is fine and they are in the same explore group. Neither of them are injured. They both have >25 BE so no special moves.
Help?