You need to have already declared an attack with it, so it has 10,000 Attack Power
Counters Examples +1/+1 Counters +1/+1 counters increase a creatures power and toughness each by 1
That said, the card doesnt technically draw cards (neither does Bolass Citadel, but that card doesnt really need support to work)
Either way, Grakmaw, Skyclave Ravager will find its way into any Golgari or Abzan decks this season, especially those that care about counters
It won't win any games by itself, but Starting Town is exactly the sort of subtle card that quietly keeps a deck running
If youve got a board developed enough for the Overrun effect to finish an opponent, youve likely got sufficient board presence to keep Garruk defended