... 
Look at what scheme a regular pool works:
Here, ordinary users are forced to look for a Hash in the WHOLE range of nonce values. And users who are connected to the pool search only in the selected segment. Hence the gain in the speed of finding a suitable hash and a greater total reward.
Look at what scheme a regular pool works:
Here, ordinary users are forced to look for a Hash in the WHOLE range of nonce values. And users who are connected to the pool search only in the selected segment. Hence the gain in the speed of finding a suitable hash and a greater total reward.
You sure this is correct ?
The stratum protocol add more nonces in the coinbase tx, with one unique nonce per worker, and the rolling happen in another nonce, the two are in the coinbase tx, additionally to the block header nonce.
All miners works on a full range nonce2, and have a unique nonce1 in the coinbase. So They all work on slightly different blocks with a full 32bits nonce range.
Not sure it affects the decentralisation principle or the main reasonning though