To close this out
Sorcerers do not have an opposition school therefore have complete access to every spell on their spell list.
Wizards CAN specialize and become a specialist or remain a generalist.
If at creation a choice of specialist is made:
They receive and extra spell memorized per level.
This is balanced with an opposition school.
Examples:
Conjuration gains the opposition school (can’t cast etc) Transmutation
Illusio gains opposition school Enchantment
and so on
https://nwn.fandom.com/wiki/Spell_school
Closing