Using StringValue instead of ObjectValue?

Since I am having trouble using ObjectValue for my leaderboard to detect a kill, I am using StringValue instead which seems to be much easier. I haven't tested it yet but I wanted to know if it'll work and the leaderboard will still read it the same as an ObjectValue.

I made a fireball tool and I am trying to make it give you points on the leaderboard when your target dies, but it's not working out. I'm using a multiple script method which parents a damage script into the part (the fireball) that you cast.