...and the little zinc on the Autoprop on our last sailboat was gone in about six months. It's just common sense to check the zincs every couple of months on a different prop or in a new marina.
As many have said, different marinas and waters can have widely different results on the zincs duration. I had an autoprop for 5 years, in 3 different marinas and its zinks (mine come with two, one bigger and a smaller one) always lasted a year, and were substituted more for prevention then for need. However, when I mounted the autoprop I have increased all the sizes of the zinks on the boat and later also increased the size of the smaller autoprop zink.
The OP says that the Gori comes with very small zinks. I never quite looked at the size of the Gori zinks, but if they are really small, that means that they have to be checked and changed more frequently.