Great example of how zam is, or isn't, useful. GG and CA out damage zam when a single hit does less than 30% of enemy hp. GG and CA tie with zam when a single hit does 30-70% of enemy hp. Zam beats GG and CA when a single hit does about 70% of enemy hp. Edit: this is in the context of over the encounter with the same opponent like jackals or high tengoku screamers.