The shorter range arquebus from STW isn't implemented in Samurai Wars. What is implemented is two different arquebuses each with the same range as archers. The Portuguese teppo has exactly the same parameters as the so called musket of STW. The Japanese teppo is a better manufactured copy of the Portuguese teppo, and has improved accuracy.

On flat ground, all ranged units have the same range. On uneven terrain, ranged units with a height advantage have an advantage in range.