>>57529389Froslass damaged Pikachu so electivire could take him out. Ninjask did significant damage to gliscor and got him poisoned which made him weaker. basically chip damage, ash needed to reveal and damage 4 of his pokemon to get through gastrodon and aggron.
Without frosslass's damage, Pikachu would have been evenly matched against electivire and so even if electivire won, infernape would have beaten him quickly. All of Paul's pokemon played an important role.