>>44225889Physical Ghosts did fine even pre-Poltergeist thanks to opposing Psychic or Ghost types being generally more physically frail than they are specially frail.
Pic related is an example of this in practice, with two Ghosts that have 100 in their respective attacking stat. Shadow Punch is much weaker than Shadow Ball but it still ultimately does more damage. Obviously this isn't the case with all opposing Psychic or Ghost types but it's still a decent generalization.