Here are some figures for Gulden CPU mining:
Now mining 269 individual miners.
Minimal 182 miners found a block the last 24h
There are 581 Blocks mined the last 24H. So you can see the wealth is widely spread and not clustered to a dozen of miners.
see https://www.dactual.com/minedby.php

a manual for mining: https://medium.com/coinmonks/mining-gulden-d4fe8c690939

But even more interesting than mining is witnessing with Gulden

a manual for witnessing: https://medium.com/@aat.de.kwaasteniet/gulden-witnessing-163cb0eae289