The Pokémon would obviously win for quite a lot of factors.

1. Magcargo has a body temperature of 18,000 degrees making it impossible for the lions to get to it.

2. How would the lions fight Arceus aka literal god.

3. Moves like surf and earthquake hit multiple targets making it so that many lions can be killed at once.

4. Swimming and flying Pokémon can just camp out the lions until the lions die of hunger.

5. Victini makes it so that the Pokémon will always win since it’s the victory pokemon.