All of this is explained on Beelzebul's Page in the JoS. The "Mammon" is just Jewish nonsense stolen from the Title of Zeus Ammon (Also called Zeus Ammonas) which was basically just Zeus. Beelzebul is Zeus, that is widely known and even know to the enemy. Many "Individual Demons" in the "Goetia", are just epithets or titles of other high ranking Gods isolated by themselves.