For witchdoctors,I can tell you.

Level 1-9 is an Enchanter
Level 10-19 is a Bokor
Level 20-29 is a Magician
Level 30-39 is a Mystic
Level 40-49 is a Mesmerist
Level 50-59 is an Oracle
Level 60-69 is a Spellbinder

An Enchanter is a basically a mage with the ability to tweak with the properties of various items,people,abilities etc.Basically,an Enchanter specializes in enchantments,enchanting items,enchanting people and such.This can be seen in spells learned at this stage,like Hoodoo Touch,which alters the opponent's abilities.

A Bokor is a sorcerer(in Haitian Vodou,) that ''serves the Loa with both hands meaning that they practice both dark magic and light magic.An example of light magic would be vulture's gift,as well as Shadow Step.An example of darker magic would be Soulreaver and Evil Eye,as well as Bone Chant(which is something the Bokor tends to be feared for.)

A Magician is someone who uses magic,to affect reality in accordance with his will.And understands it,applies it and gives it some sense,as a scientist of the unknown.Big Juju is an example of such a spell.
A mystic,unlike a magician,focuses less on changing his environment as much as changing himself.A mystic is basically someone who tries to ascend more than he wants to change the world around him.And the mystic focuses more on internal change than external change,an example of such a spell is Charm,which sways the opponent to the mystic's benefit,by either making oneself more ''charming'' and easier to follow or tweaking with the mind.

A mesmerist,is basically someone who knows hypnosis,and uses attraction(at the time of F.A. Mesmer called animal magnetism).On a deeper level,however,it is also the illusionist,the alterer,the one who produces change or doesn't.It also has the nicest ring to it(IMO)