You can make scoundrels and huntsmen who deal more damage than warfare builds, but absolutely not magic users.
Its simply because physical does not have resistances and magic does. Most enemies from Act 2 on have multiple resistances, and very rarely a elemental weakness. So while a physical character is dealing 500 damage every hit, your magic user is hitting 500 damage minus elemental protections.
I modded out all elemental resistance from the game for my all mage team, and things are dying about as fast as I'd expect on an all physical team. The CC is still pretty weak, though.
This doesnt really matter though. The game is easy and you wont be challenged even if you make a sub-optimal build.
There is still a challenge in RPGs that are "easy," though, and that is the challenge of efficiency. Pokemon is a very easy game, you can beat it with literally any permutation of Pokemon. But you can definitely optimize you team to beat the game
better.
Think of it like a speed run. For a speed run, the question isn't "will he beat the game?" That's only a goal by proxy. The actual goal is some other, meta-level achievement: beating it
faster than other people.
