I should probably add that this isn’t a bad idea either, depending on goals and playstyle. If you prefer his higher attack, then attack path makes absolute sense – his stats lean that way.
To deviate a bit with Grimm, I use him myself to compete in monthly challenge events, and I emblemed mine towards the attack path for that reason.
But most other players I know chose defense path, and frankly I think there’s different roads to success with Barbarians like Grimm, Little John and Gretel. See this conversation:
I myself don’t use mono-green often for events or quests, it’s mostly raiding. So that’s why I prefer my L.J. focused on defense.