The obsolescence of policy cards are kind of annoying. Having too much Culture give you the cards earlier. I don't know if it's a balance issue to make Culture civilization somewhat weaker, but I would like to see this:
Feudal Contract: +50% Production towards melee and ranged units from Renaissance era or earlier.
Grande Armée: +50% Production towards melee and ranged units from Modern era or earlier.
Military First: +50% Production towards melee and ranged units from any era.
Chivalry: +50% Production towards heavy and light cavalry from Industrial era or earlier.
Lightning Warfare: +50% Production towards heavy and light cavalry from any era.
Press Gangs: +100% Production towards naval units from Industrial era or earlier.
International Waters: +100% Production towards naval units from any era, excluding Carriers.
Strategic Air Force: +50% Production toward air units from any era, and Carriers.
Gothic Architecture: +15% Production towards wonders from Renaissance era or earlier.
Skycrapers: +15% Production towards wonders from any era.
Bonus: Naval units from medieval era have now their +100% cards! Well, we don't have medieval era naval units today, but someday maybe we will!