Sort the data by finding out which trainer has the strongest pokemon so that this will act as a ranking of strongest to weakest trainer. You may interpret strongest in whatever way you want, but you will have to explain your decision.

Explanation::
I sorted by average pokemon level of each trainers. Then trainers with the same level, I sorted by who has the most pokemon. Following that, i sorted in alphabetical order.

SELECT ANY_VALUE(pokemon.pokemons.name),
       pokemon.trainers.trainername,
       ANY_VALUE(pokemon.pokemon_trainer.pokelevel),
       ANY_VALUE(type1.name),
       ANY_VALUE(type2.name)
FROM pokemon.pokemons
       CROSS JOIN pokemon.pokemon_trainer ON pokemon.pokemons.id = pokemon.pokemon_trainer.pokemon_id
       CROSS JOIN pokemon.trainers ON pokemon.trainers.trainerID = pokemon.pokemon_trainer.trainerID
       LEFT JOIN pokemon.types AS type1 ON pokemon.pokemons.primary_type = type1.id
       LEFT JOIN pokemon.types AS type2 ON pokemon.pokemons.secondary_type = type2.id
GROUP BY pokemon.trainers.trainername
ORDER BY AVG(pokemon.pokemon_trainer.pokelevel) DESC, COUNT(pokemon.trainers.trainername) DESC, pokemon.trainers.trainername