I
You can, in fact, test this in game already without any alterations: Play any character that can access both Find Familiar, and Mage Hand. Because Mage Hand counts a s summon int he current game implementation, summoning your mage hand immediately kills your familiar, and summoning a familiar immediately dispels your mage hand.
Than, Larian really wanna kill necromancers.
Why noit just remove the wizard subclass?