>>26530386This is how I like to think of it. I also like to think that Gym Leaders use different Pokémon and teams depending on how many badges the opposition has (a la Pokémon Origins).
So in theory, Roxanne is just as strong as Wallace. However, if you fight her first, she uses a weak team to match your skill level. That's why Gym Leaders can step up or step down the ladder.
That's also why Cheren becomes a Gym Leader and uses weak Pokémon. We already know he has an extremely strong team of Pokémon from his past adventures, but he puts them aside when you fight him because you have no badges.
