What is Common Initial Setting of Laser to Completely Remove Men's Beard?

My boyfriend is skin type 2 and his laser was alexandrite. Initially, setting was 8J and was increased to 9J for his touch-up, which was 2 weeks after initial shots. After 3 weeks from the initial shots, only 5% of beard is falling out. I heard that beard laser removal with alexandrite at least needs 12J. Is that true? I understand that facial skin is thin and beard is dense, so laser removing beard is difficult. Does he need diode laser instead to safely increase setting to effective strength?