There's a great solution: don't attack with 30 Goblins and 15 Gargoyles against 40 Archers. If those "Archers" are also Goblins or Skeletons, they won't do much damage, so you can attack then. In general, divide the Gargoyles into several stacks and place them on the battlefield. You use Archers/Fists/Spikes yourself, preferably with a magic bonus if you have one. However, 40 Archers can't possibly guard wood and ore, even on a hero and a map with strong monsters. And the rest can survive for a week; it won't hurt you. Anyway, for the first couple of weeks, you're building almost every day.
On a hero.