Enchanter changes drastically after 12 once you get your first charm.
Necros are not desired for groups, and you'll pretty much solo to 60 focusing on charming undead.
Necro requires less gear, but you'll need a
Circlet of Shadow as soon as you can get one (clickable at level 20).
It's highly recommended to be an iksar necro. You don't *have* to, but it's more optimal.