So,after chapter 1072 i thought Tashigi could be Kuina's clone,but still i dont think there is a valid reason so far on why Vegapunk should clone a simple girl like Kuina. Unless Koshiro have some bonds with Vegapunk somehow,it doesnt make much sense. Unless both Tashigi and Kuina are clones of someone else,and Kuina was adopted somehow by Koshiro.