You may decide to go for house rules. That's what I did, creating a Sengoku version of "Dragon Rampant" using the sonae as the base unit. Each sonae is represented by 3 stands - one with mostly missiles, one with the bushi, and one with the commander and banner - and the arrangement of these stands shows how the sonae is optimized (I simplified the various formations to three: "Birds in Flight" for most maneuverability, "Arrowhead" for strongest attack, and "Keyhole" for strongest firepower). I've playtested it with my club a couple of times and I'm fairly pleased with it.