Let’s take a moment to examine measuring movement, and how exact a player needs to be.
The first thing to consider is how exact are the movement rates. They are, after all, based on Kriegspiel movement rates, as determined by officers of the time. I definitely think this makes it a great place to start, but there are two huge areas of “fudginess” that place a limit on how exact those movement rates can be considered to be.
The first is that every foot and every mounted block moves the same. If a block is travelling the same straight path a few turns in a row, then it might be considered to be moving the full 90 minutes of a turn (one movement stick). A similar block might receive new orders. One can imagine the formation commander interpreting the order, issuing new orders to his command, who then might have to react to a complete change of plans, who might need to verify the orders, get their men moving in the new direction, maybe scouting the terrain to determine the best path (more on that in the second point), move to the new location, where they might possibly be involved in combat, which itself requires some further maneuver and giving/interpreting of orders, all that, and they too can move one movement stick in a turn.
The second consideration is the terrain penalties. If a block moves through any terrain that reduces it’s movement, say a grove of trees wider than 1/2 a block, or moves the entire time through woods and over hill and dale, it loses one third. This is not some arbitrary amount, this is how the Kriegspiel rules work. Such an adjustment was considered “close enough.” The terrain itself can be varied. Are there wide paths through the woods, or are they thick and almost impenetrable? How steep is that hill? does it include cliffs, washouts, or large boulders (great for cover, impossible for artillery)? In the grand scheme of things, when you are talking about moving a few thousand men, such variables get handled, and Pub Battles docks the formation a third. That is “close enough.” For everything else, there is the chit draw to determine who might have got where, and who might have outguessed their opponent.
One should be satisfied with “close enough,” because it is a fact of life that the map and blocks are going to get jostled. When I’m moving, I use a divider and walk it out however far it says I can go, and that’s where I move to. If I come to the end of my move and am close enough have interlocking Fields of Fire, I just go ahead and move to contact, or stay out of the FoF. Battlefields are fluid and chaotic, and within reason this allows a little slippage in measurement. How much? Enough to allow smooth play, but not so much as to allow one to game an advantage. Gentlemen’s rules.