Maybe we should stop resorting to made up, arbitrary rules that barely make sense, if we want to predict Oda's plans accurately.
Besides, a guy who has something akin to toon force and can do stuff like grab lightning, is hardly a mere brawler.
You’re forgetting that “toon force” (which Luffy doesn’t have but okay) is still primarily brawling… Like bugs bunny and tom and Jerry and Popeye are always physically brawling on top of their “toon force”
No one is “a mere” anything in one piece… Zoro isn’t a mere swordsman, he has several abilities that have nothing to do with swinging a sword… and yet he’s still a swordsman and Zoro’s last fight will most definitely be against a swordsman
Luffy similarly has other abilities on top of his brawling but he’ll still remain a brawler… And I’m not making up a random rule here, Oda himself simply doesn’t like drawing Luffy vs magicians… For example Imu is basically Gecko Moriah (the one and only magician fight Luffy has ever had)… Gecko Moriah also summons minion zombies (remember brook called The holy knights zombies) , his can also summon his shadow to fight for him, his shadow can transform into demonic creatures to fight too, all this without Moriah lifting a finger… Moriah even has a one hit kill ability of just stealing your Shodow without any brawling required.
and yet what did Oda do when Luffy was against this magician fighter? Well he made Oars the primarily opponent instead so that the fight can become a brawl and then Moriah used shadows Asgard to try and become a brawler himself and Luffy just punched the shadows out of him and that was it
Oda went out of his way to turn a magician fighter into a brawler because Luffy is a brawler and that’s how Oda likes his Luffy fights to play out… Teavh being a brawler and Imu being a magician HEAVILY CHANGES the odds on who becomes the final villain