You're correct about Chinese rifles. This still equates to 20% more damage however. Korean rifles at 40% more damage are still superior however.
I really wouldn't say that .
You'll lose more chinese shooters vs shooting defenses than you'd lose korean ones.
The reason is , that chinese shooters need to shoot more times at fir example a Tower , than korean shooters.
With IA or higher Age it makes really huge difference.
IA or higher korean shooters need to use only 35 shots at max to destroy lvl 7 tower , where chinese need to shoot 55 times at the same tower to destroy it .
Both korean and chinese shooters have range of 4 which means that they are vuknerable to towers shots before they get in range to attack .
Bringing 35 shooters to a battle means that koreans can destroy a tower with first shots at it where bringing 40 chinese shooters means you need to attack twice at the same tower to be able to destroy it.
in the long run that means that you lose more shooters in the process of destroying defensive buildings.
Both nations shooters are good, but both give different advantages.
Korea shooters are better than chinese thanks to their dps boost at destroying buildings
Chinese shooters on the other hand are better at killing defenders since those need to come closer to be able to kill your units, and that's where chinese shooters increased attack speed is far more better than dps bonus of korean shooters.