Historically, eversince the daimyo of Tanegashima island bought two matchlock guns from Portuguese merchant, the "teppo" drawed attention of major daimyos during the senkoku period because of it's powerful armor-piercing ability. Unlike bow, the bullet fired from teppo had sufficient power to crush the armor and kill the objective. Also the teppo didn't required much training while bows aren't. Oda Nobugana, who was one of the daimyos noticed such potentials of teppo, has won the battle of nagashino tactically using teppo troops, changing the phase of senkoku period. Soon the teppo became important component in Japan armies.

But the firearms in the game are just too weak! You've got to shoot at least two or three bullets to kill an fully-armored high tier troops, even with "heavy teppo" and bullets. This is way too underpowered. The balance might be maintained by decreasing the accuracy and reload speed, instead of lowering the power of single shots.

It is too sad that the devloper abandoned the mod and those firearms would remain in the current, historically-uncorrect state forever.