>>58064338Pichu is technically slightly better in a situation that will almost never come up.
If you added two Fire and a Lightning energy to Oricorio because you only had Magby and Oricorio for two turns, and then you lost the Lightning energy because of a random event like Gyarados ex's attack, you'd be down in the energy economy as you need to attach another Lightning to Oricorio if you want to attack again when you could attach the Lightning energy to something you just drew in another world where you used Pichu.
They're practically the exact same except for this one never ever happening scenario, but it would be really funny to lose when you otherwise would've won because of it.