Based on another skillset?

"Crash Shot is one of two ranged skills that was based on another skillset, the other being Arrow Revolver. " What does this mean? So much confusion. Please consider revise or remove this sentence...

“	A skill that fires an arrowhead, which senses enemies using the same principle as an Ice Mine.	„
—Crash Shot Description

I still don't see how it relates. The statement in question says that Crash Shot and Arrow Revolver are based on other skill sets. I can understand Ice Mines being "based" on Ice Spear, but I don't which skill Crash Shot bears such relation to.

It means that crash shot explodes when it hits an enemy, striking those near it, like how ice mines explodes upon contact with an enemy.

Ice Mine is also technically a skill.

I believe it means to say that Crash Shot has ideas borrowed from alchemy because of how it behaves like an ice mine while Arrow Revolver has ideas borrowed from magic because of how it behaves like Icebolt. Therefore, both of those skills are based off of separate non-archery skillsets.

Now it does make some sense :) thanks.