I not sure categories of Rajput Gorta , but same Gotra marriage is not done primarily to have healthier children. The reason is the more the blood mix the better the children. As we have seen that genetic and hereditary problems more in people who have marriage in families etc.
Having said that it is not like compulsory by law or by any religious books but a social system what has been followed.
Blessings,
Navneet Khanna
Astrologer