Why is it when you upgrade a weapon to its next tier, it's extremely strong, and more strong then it's counterpart that you would find in a supply drop?

For example, I had a primitive crossbow and upgraded it to a ramshackle one, I had also found a ramshackle crossbow in a supply drop. The crossbow from the supply drop had a much lower damage percentage compared to the ramshackle crossbow that I upgraded.

Is there a way to change this? I really like this mod, but don't want to have access to overpowered weapons, because I feel it makes the game too easy.