^ Yes, their carbon knives are easier to sharpen than their stainless. Neither takes crazy amount of effort though, imo.
Edit: in their words,
As any quality steel goes, stainless or carbon, all knives should be kept cleaned and oiled to prevent rusting, but especially in the carbon steel knives. They tend to hold an edge longer and sharpen up faster than the stainless, but they will corrode if not kept cleaned and oiled at all times when not in use.
https://www.grohmannknives.com/index...terials-we-use