>>58535454I might be best qualified to answer that.
I finished this game on an emulator for no other reason than seeing if more modern titles were still working on forks after Nintendo took Ryujinx and Yuzu down. I had no idea what I was doing combat wise, skipped all the story text, and was literally button mashing attacks I hadn't bothered reading details of. If I saw it say something wasn't effective I just swapped to another pokemon and kept mashing and healing.
So, yes. You can indeed beat it with weirdo picks and a handful of pokemon, you can even beat it without knowing what your attacks even do.