Zoro is the role model even in real life. Without power, he is still a very admirable person.
Sanji? He would be a pervert chef who ends up in jail forever due to sexual harassments
Luffy? Without luck and power in reality, he will be annoying as f due to his stubbornness and lacks of logic. He'd also be dead and never reach adulthood. No one wants to be like Luffy unless they want to be a jerk.