In the early 2000's, my friend Bob McDonald introduced me to these house rules for adding semi-double-blind approach moves to grand tactical games. I loved them.

These were developed for Volley & Bayonet, but could be adapted to any sufficiently grand-tactical set of rules.

I love the fog of war these rules introduce. Like a real general, players really don't know exactly what they're facing or precisely where the enemy is, but do have a general idea what they are up to. This in turn makes scouting into a real and critical part of the game, a feature of historical battles rendered irrelevant in most tabletop games, or just left out for convenience. It is also possible to ambush an adversary by clever movement and placement of blocks before they must be replaced with real miniature units, which avoids many of the problems with secret deployments, especially the "could I/couldn't I" arguments that make everyone into a rules lawyer.

I also love the automatic adjustment of the gamer's thinking into a grand tactical mindset. Long lines of blocks tend to clog up a road net, forcing player-generals to think carefully about the orders and directions of march. Terrain is selected by players rather than dictated by the scenario, since the armies begin out of contact and have options. Forlorn events like Picket's Charge suddenly make more enjoyable gaming experiences, since they happen naturally as a result of player decisions (or indecision) and only involve a portion of the army.