Question about OC groups based on blood ties

My question is how do OC groups based on blood/family ties avoid the problems that come with such an arrangement ? Such as ( for example ) inbreeding ?

Marriage. Ties by marriage are still as good as blood ties, in traditional societies where divorce is unheard of. I'm talking about Albanian OC since I am Albanian and you asked about blood ties, and they're one of the few OC clans which are almost exclusively blood-related.

I bet in nyc theres still huge marriages between some made guys niece and a son of some one else. I know no one wants to here about vicky gottis sons one of them got married in that castle thats all mobbed up on long island tons of money. It was in all the papers. Probaly just pre publicity for the upcoming movie about th ere grand pa.

Do members of Albanian OC groups marry civilians ? If not then how do they deal with the issue of needing fresh blood ( for lack of a better term ) ?

I mean there are only so many Albanian OC groups in existence , therefore I imagine it becomes necessary at some point for certain members to marry outside the circle of organized crime in order to stave off inbreeding and such .

Also if marrying civilians is allowed then how do they deal with the issue of civilian relatives ? If ( for example ) a member of a OC group marries a woman from a family with no ties to OC , then does said member's organization try to involve said woman's family in OC activity ? Or would said woman become isolated from her family in order to stave off sensitive information from leaking out about her husband's organization ?

Anyways thanks for the answer .

concerning italian mafia they usually married only people more or less linked with organized crime, rarely people outside their circle
they need somebody who knows mafia rule who grew up with that mentality

In the ndrangheta the families decide who of their children will marry the daughters of another ndrina, and if a girl, for example, refuses to marry, is abandoned by her family, and sometimes her brother or her father must kill her to restore the family honor .