Amongst the volunteers of the small plasma-gun wielding unit, Gaark and Hannah were one of them.
Aware of the severity of what the tribe was up against, they were among the people who were comfortable with holding, and working the guns. They were trigger happy, basically, and could not wait to shoot their guns, so they didn't wait for their turn.
Although he was physically able to wield an average-sized gun, Gaark was given a plasma pistol, because Anna knew him enough not to trust him with anything bigger.
Gaark did not wield Dinosaur Strength, for one thing, but he was as frantic as a man who had such abilities! He jumped around like a frog, and was not scared to meet large, apex predators eye-to-eye.
It was not ideal to give a man like that a big gun. Anna could easily predict the accidents that would happen, and now, since he did not wait his turn to test out his plasma pistol through her guidance, Anna was right to give him a puny little pistol.
