There's a lot more context to it. They hit Cap and T'Challa's blindsides when they got them on the ground and used weight of numbers to unbalance Hulkbuster, causing it to fall over, which made Banner start to panic.
The humans in question were largely Wakandan soldiers (a country that greatly values combat and martial prowess) who were mostly armed with vibranium weapons and armor (it's stated in Black Panther that they weave vibranium through their clothing) that had energy projection and shielding capabilities. Even without utilising the energy shields or blasts, those "sticks" could do things like this:
https://thumbs.gfycat.com/FirsthandChubbyAmericanredsquirrel-mobile.mp4
A small faction, the Jabari, used traditional weapons. But the only one there who had any significant success was M'Baku, and he is one of the best warriors in Wakanda (being able to hold the upper hand against T'Challa for a large part of their ritual battle for the title of king) and has borderline super strength himself (as shown in the clips I posted earlier where he is ragdolling grown men by hitting or tossing them around). And, despite killing some of them, they were losing the battle and taking a lot of casualties themselves until Thor showed up.