[Question] Help changing Partner script to fit with my idea

[SuperGoldSonic]

So I've had an idea for a game where you have partners who act like party members in a JRPG where you're able to control their Pokemon's actions. It'd be a 3v3 game where the player character and two partners would go into battle. Ideally, I'd like to have it so that the player character has access to a full party of 6 but the partners only have access to one Pokemon and can't swap out with the player character's Pokemon.

I'd like to be able to have two partners registered at once so I'd like to know how to fix this script in order to have 2 partners at once:

def pbRegisterPartner(tr_type, tr_name, tr_id = 0)
tr_type = GameData::TrainerType.get(tr_type).id
pbCancelVehicles
trainer = pbLoadTrainer(tr_type, tr_name, tr_id)
EventHandlers.trigger(:on_trainer_load, trainer)
trainer.party.each do |i|
i.owner = Pokemon::Owner.new_from_trainer(trainer)
i.calc_stats
end
$PokemonGlobal.partner = [tr_type, tr_name, trainer.id, trainer.party]
end

Would there be anything I need to change in the Overworld_BattleStarting section of the script?

How would I find and fix the def pbOwnedByPlayer? section in the script to make it work with the idea?

If you could explain all of this like I'm 5, that would genuinely help!