Not only did this chap confirmed family genes enhances your body. It also enhances your potential. Momo can now become the strongest swordsman in Wano because of Oden body and potential given to him.....
Now how does that apply to Zori. Well he has the genes and potential of Ryuma's genes bestowed to him. That's far more given to him then any training ever gave him. Take away his Shimotoski genes, and he's no where close to where he is now. Same goes for Luffy and his Monkey D. Genes
Poor Sanji has been keeping up with these 2 gene Monsters for 2 years....until his enhanced genes kicked in this arc. Imagine being grouped with them, without your own genetic potential given to you...
Now Sanji unlocked his genes.....and he's blown far past Zoro.