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?