Actually if you look at the Warren map there were up to nine fence lines that had to be passed through. That would almost be every hex in our game would have a fence.

The problem from the gaming point of view is how many were real obstacles to movement? That is hard to say. Some were post fences which compared to worm are probably relatively easy to knock down and provide little cover unless a regiment makes a breastwork out of them. The worm or zigzag fences can be quite formidable structures and can provide very good cover. They can't be just pushed over like a post fence. The problem here is how many were still standing after two days of fighting? Did the Rebel brigades properly handle their advance by sending out detachments to tear down these fences before the line reach them?
Then there are the fences that ran the same direction as the charge. These tend to channel the regiments since they must follow the fence line. Part of Pickett's division had only one worm fence to cross and a couple of post fences. But Garnett and Kemper had to angle across the frontage and crossed about seven fences.