With 25 cards, i think there is enough room to have both eco upgrades and military improvement cards.
I think the Refridgeration, Royal Mint and (top) Plantation upgrade is a must, wood upgrades are less important (you have factories, that should be enough to spam artillery with the +50% on coin gathering you have already), plus food for musketeers/whatever.
40 mins is a long time though...
btw, does culling your villagers help all that much? do you find youself able to knock out your enemy with your first blow (due to larger military pop space), or do you find that they can rebuild fast enough to make it not worthwhile?
As an aside, you could try not culling your vills, and then build three different depots, i suppose you call them: eg, have two or three stables, five barracks and 2 or three foundaries in your base up front, and another one off to one side of the map, and a third on the opposite side. And then, once your army has engaged your enemy's army in the front, then build the replacement units from one depot on the side, and attack the enemy's base directly - he'll prolly recall and knock you down due to superior numbers. but by the time he has rebuilt and is moving forward again, you've resent from another direction so he has to recall and intercept that, etc. It can be quite demoralising never getting to attack the enemy's main base, and with your superior economy you should be able to maintain the losses for a longer period of time than he can - its like forward building in rush games, but 40 min NR styles :\
btw, i'm surprised that no-one's mentioned the sandwiches yet?!
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