The indians had white man's arms , so if the wonder tools were there for the soldiers , they probably would have been there for the Indians.
Custer did not take along the Gatling Guns he had available, he is responsible for the failure, no one else.
American Indians rarely gather in fighting groups , i.e. multiple nations; they did that day, -- at that, had the Indians used the European long bow it would have been nastier.
In Eruope a long-bow man, had to prove they could hit a target butt at 220-300 yards, depending on which military person set-up the range.
The size of a longbow target butt can vary, but here are some examples:
Traditional longbow target butt: The target front was about 7 ft (2.1 m) high, 4 ft (1.2 m) wide at the bottom, and 1 ft 4 in (0.4 m) wide at the top. The butt was 9 ft (2.7 m) long behind the front and tapered into the ground. The target face was a small piece of cloth or pasteboard disk about 4 in (10 cm) in diameter.
So U.S. settlers should be glad Indians did not have Long-Bows.