There's no strength-based yet small sized creatures that sit at low difficulty levels in D&D, so Blunders are just Goblins but their STR and DEX stats get swapped out. Also instead of having a lot of mobile or nimble traits associated to them, Blunders instead have a natural ability to force successful actions that they're observing to become failures. Capitalizing on the saying 'every failure is a goblin' that came about from AD&D.