Page 126: Scoundrel:
• Armor: Light armor
• Weapons: Simple weapons, hand crossbows, longswords,
Page 128: Explorer: "Wilderness-master You gain proficiency with the Nature and Survival skills along with the Longbow."
As we can see from this the only martial ranged weapons the Explorer gets is hand crossbows and longbows. However, the longbow has the Heavy property:
"Heavy. Creatures that are Small or Tiny have disadvantage on attack rolls with heavy weapons. A heavy weapon's size and bulk make it too large for a Small or Tiny creature to use effectively."
Is this an oversight? Or are goblins meant to use simple ranged weapons and hand crossbows?