I feel like garen is too strong right now.
If he gets 1 kill, the game is over. He will snowball the top laner into oblivion, and then roam, get a few kills, finish black cleaver. Then the game is pretty much over.
And now, the classic garen combo:
1: q for insane burst and silence
2: e for insane damage over time and cc reduction
3: and if the enemy even TRIES to trade with you, just w and you will be fine.
With that said, there is counterplay to him. Usually a champion that can kite him, like a vayne or quinn top. But that's about it.