The turret buffs are rather insignificant. The damage and accuracy isn't the issue, it's the health and fire rate that needs looked at.
The mini turret especially least needs to be looked at. Give it the damage, accuracy and fire rate of the machine pistol and there you go. Your weak, but rapid close range support turret.
High fire rates at low damage create a lot of spam in the health tab which I'd rather avoid so don't anticipate a lot of increases here.
DPS is proportional to all three: fire rate, accuracy, and damage.