Vlad Tepes III
Chieftain
Once steam engine has been discovered and you can build a substantial fleet, there should be NO GROUND COMBAT whenever applicable. I've found that sieging a city with musketeers fortified inside, can be a terrible meatgrinder if a blitzkrieg-like strategy isn't applied. This is assuming you are fighting a non-landlocked country, with seaports. Destroy all units in the city with the fleet, if you can't do that then blast them with cannon, and THEN swarm with infantry and calvalry. Ideally, this will save many units of infantry.
A lightning fast invasion can be accomplished with loaded galleons and ironclads. Ready the pieces two spaces from the cities, in the ocean. When ready send in ironclads and blast the city until defenseless and then move the galleons in and send an appropriate amount of ground troops. Island nations can be eradicated in one move.
After this point in science it just gets easier. Planes and tanks make it easy to duplicate a German-type blitzkreig invasion. That is, if anyone is still alive by that time.
A lightning fast invasion can be accomplished with loaded galleons and ironclads. Ready the pieces two spaces from the cities, in the ocean. When ready send in ironclads and blast the city until defenseless and then move the galleons in and send an appropriate amount of ground troops. Island nations can be eradicated in one move.
After this point in science it just gets easier. Planes and tanks make it easy to duplicate a German-type blitzkreig invasion. That is, if anyone is still alive by that time.