A) Via groupware
These devices are often already linked to a personal groupware account (Google, Apple, Microsoft). Create a sync.blue® connection per user/smartphone, to sync contacts from any source with this groupware account.
When it comes to many smartphones, first create a single connection and Then "share" them with any number of colleagues!
B) Via CardDAV
Just create a single connection that your contacts from any Target with a CardDAV server (either your own) or that of sync.blue® synchronized. Then enter the CardDAV access data in your smartphone so it can access the contacts.