Culture in Civ VI.

[Gali]

I wouldn't worry about generic governments. Even if the regular ones are generic I am sure mods will have crazy governments out quite quickly. policy cards also sound like something easy to tweak and expand on with mods.

Also unless the balance of cards is REALLY bad governments will be less unique. You and another civ could both be classical republic. But if half your cards are different its not that similar a government.

 

[AriochIV]

The governments will have limited variation in slots, but the policies that you have to put in those slots will depend on your civics choices, so there is the potential for significant variation.