its not likely to do 5 points of damage unless you happen to shoot at a 3 hull fighter and roll well.
A tie fighter has 3 hull each worth 8/3=2.7pts. So you have to do two damage to a tie fighter for it to be worth 5 points.
There may be more value to be had elsewhere, but cluster bombs IS worth 5pts when activated.
If you don't kill the tie fighter all the way you get no points ![]()