Legendary Cube rates on weapons too high?

I personally have not legendary cubed a weapon so far, but from every person who has, they seem to all have easily gotten multiple lines of boss damage. Im not a pessimist, but everyone and their mother getting 60%+boss easily on their weapons doesnt seem intended. Heck, a friend of mine got multiple lines of % boss 4 times out of 5 cubes that he used. This is making me think that either the % boss rates are naturally supposed to be this high, or that nexon america accidentally made them so. Can anyone in KMS confirm or deny this?