Factual error: In this episode - in 1942 - streptomycin is used to cure anthrax infection. But streptomycin was first isolated in 1943, and first used successfully - on Sen. Bob Dole - in 1946.
Factual error: Fort Benning is stated to be in Virginia. It actually spans the Georgia - Alabama state line.
Answer: They are using the accepted names of the bombs. During World War 2 the Germans used the metric system and produced bombs ranging from 50kg to 2500kg. Referring to the weight of the bombs in pounds (or fractions of tons) risked confusing the situation and would require someone to understand how to convert from imperial measures to metric, not an easy thing to do when under stress.