Is it a bad practice to change the timescale for the whole game?

I have a player that shoots out projectiles (arrows). Since they do not move instantaneously, I transform.translate to move them. However, they travel very quickly and "skip" along the screen with each frame. The problem is collisions. If the arrow is too fast, it may skip through an enemy. (The game is 2D by the way.) The arrow can also pierce for an X amount of times. If I want it to pierce for example 1 time before destroying itself, but there are four enemies in the same spot, all collision events happen simultaneously and it pierces 3 times instead of 1. I've tried to illustrate as best as I can here: I've tried different kind of movements for the arrow, but so far I didn't find out anything worthwhile. The only thing I can think of is to raise the Timescale and lower variables such as movement speed, animations speed, etc. My only concerns are if this will change time.deltaTime and if it is a good practice whatsoever.

My question is about changing the Timescale, but if you have any suggestions about how to better handle the arrow movement, I'm open.