I remember with the version of Pirates! that I had that I spent almost as much time on the land as on the sea. I would frequently hike between the towns located along the Spanish Main because you could only bring as many men as would fit on the single boat that you were using to attack the fort, if it had one, of the city that you were attacking, but you could bring almost all of the crew if you disembarked from the ships and attacked from the land. I remember the chance of taking over control of the town, and setting up a governor from the country you were working for, largely depended upon how many troops you had at the end of the battle.
You would get three groups of men that you could direct to attack the fort on the battle screen, and you had to deal with various types of terrain and blocked lines of sight, along with the likelihood that if you vastly outnumbered the enemy, they would hightail it back to the (relative) safety of the fort and though you might still gain a victory, it would often turn out to be a pyrrhic one.
One of the things I most enjoyed was using the terrain to hide my stronger units and use the weaker units to draw out the enemy force, often making the foe cross swamps or marshes in the process, and then unleashing the trap that I had set up upon them by moving my strong units into shooting range, usually still under cover, where they could fire upon the badly positioned and frequently panicky garrison troops. Usually I could wipe out most of the enemy force before I had to take on the otherwise meatgrinding forts.
As simple as the original game was by today's standards, it still had fun things that you had to deal with. I remember, on more than one occasion, watching my own troops breaking and running away and having to "convince" them to go back into harm's way. I also remember how only one man in four in my army was equipped with a rifle, but it was something of a relief to find that usually the enemy troops had fewer guns than I did. You were not always certain of where the fort was located and you could spend a lot of time searching for them before you found out that you were hopelessly outnumbered by the garrison stationed there.
I haven't played the Gettysburg game, but if it is like the original Pirates! at all, with some of the features above, then I can only anticipate that it will really add to this game.