There's really nothing devs could do to affirm balance when it comes to tweaking speed without steppin' on toes, in my current opinion, but maybe they could add more countermeasures and graphical disadvantages that influence tactics taken and provided. Not just for this rifle alone, but to make every firearm and sword have their unique immersive feeling thorough diversity of purposes.
You know, to deliver the offered fantasies properly.
Edit:
For example, add more activities into the game that utilise only certain items. Add more optional items into the game that affect each voyage differently in a challenging way. Make the body types change how the mates react and solve the challenges of the environment, but in an equal pace and promoting diversity of the crews.
More about this subject in the [MegaThread] Predictions & Ideas Part 1 and 2.