Luffy is coc specialize only mean luffy coc>luffy coa/coo
Luffy is a natural coc user this si why he did not needed anything toehr then some steaching to get acoc .
When zoro it is a long story how he got it but basically because of an extraordinary situation zoro got acoc right after learning he was a coc owner he even never used classic coc before using acoc .
So ye sby defualt luffya coc is stronger and more refine also luffy used the combination of acoc and ryou this is why his attack do not make contacts zoro can't do that I never saw zoro not making contacts except with his long distance attacks.