Would it be possible to break some of these categories down by fighter? Might make it a bit more attractive to run if there are options other than the Can strat

Creating subcategories for each Fighter would just unecessarily dilute the leaderboard, (example: https://www.speedrun.com/fast_rmx/full_game#Single_Cup )

The way the Leaderboard is set up right now, you can choose to view all at once, or runs with a specific Partner Pokémon. To do so, press the "Filter" button at the top right of the leaderboard, then select "Partner Pokémon", whatever you choose here will be shown on the leaderboard.