The battle of Greasy Grass played a big role because after the war it made it harder for native Americans to defend their land since it inspired other countries to attack the native Americans. Not only that but the USA dint respond well to Custer’s defeat and they increased their force. The ‘big picture of this war’ is that the war gave the native American’s a bad reputation and made them look like blood thirsty people which eventually led to the USA to rethink their strategies when preparing attacks. Victories within native American wars had a big impact and were seen as a sign of hope to defend themselves against colonizers.
https://www.historyhit.com/why-was-the-battle-of-little-bighorn-significant/