Dude. Zoro carries a sword in his mouth, not.... Okay, that's your business, but then wash it. By saying that Zoro is the strongest mugiwara, you are showing your bias. First of all, Goofy is not alone, he is always with Nika and Joy boy. This is his strength. Zoro is lonely and achieves everything by himself because he is too proud. And this is bad. Training and haki = this is not all that is needed in life. Goofy, for example, after losing to the admiral, just decided to have a snack, leaving the fight to his friends. All Zoro can do is fight and drink vodka. Goofy is a more cheerful person.