it goes back to the nature vs nurture debate. How much of what we do is based on genetics and how much is based on events that happen to us. They may be genetically similar but they no doubt have different personalities and interest.
Environment has some say. If a care provider neglects to care for one twin while helping the other, then it makes sense that he/she will have a one-up. Genetics determine the range, but environment and other acting influences are factors in this matter.
Genetically the potential is there for the other twin to excel, however for one to excel at anything there is the added necessity of that rare component: practice!
Without it, all the genes in China won’t amount to didly!
My brothers are identical twins. One excelled in music, getting a full scholarship to college. The other went to college by excelling at football. Both had the same opportunities. Both took music lessons and sports. They just chose different paths in highschool. Their wives are total opposite personality types. As adults their lives are so different. Nothing will ever change their feeling of closeness that only twins share.