alright. Thanks

So as a pool operator/developer one of the most important things is to make sure that every single miner connected to the pool gets different work. ?
Which is controlled by the nonce/extranonce  each miner gets, right ?

For my understanding , nonce itself is to small for modern miners anyway and overflows under a second. So miner starts changeing extranonce, which is also just a number that will be incremented?
Question: How is guaranteed that every single miner realy does unique work. ?  How is secured that each miner changes nonce and extranonce values differently to make sure no duplicated shares are created.