My daughter played a sport, and we ran into many twins on other teams, more than would just be a coincidence. They obviously were recruited together and of course there is no way to tell whether one was more talented athletically and the other academically, but it was clear that the schools/coaches knew they wanted to stay together.
There are twins playing for Navy, recruited together. Often there are sisters a year or so apart who were recruited together too. We had siblings commit to our team but when one didn’t make the academic cut, they both went to another team. Together.
I think for the OP, it is unlikely being a twin would be enough to bring the lower stat applicant up. If they are recruited athletes? Maybe. If they have some other unique quality the school wants? Maybe. Just being a twin isn’t enough, but it may be enough to get the twin looked at where otherwise the stats just aren’t there.