I'd start with something free like Basic Impetus
PDF:
http://www.dadiepiombo.it/images/stories/dp/bie08nov.pdf
Army lists:
http://www.dadiepiombo.it/images/stories/dp/vol34e.html
Army lists for other periods (scroll down):
http://www.dadiepiombo.it/images/stories/dp/basic2.html
The figure count can be as high or as low as you like as you basically make stands or movement trays and then put as many miniatures as you like on them.
Some people permanently attach their figures and make little dioramas, others use movement trays. Others get laser cut bases with little sockets to put their figures in.
There's one rules module missing from the free basic version of the game. Light cavalry and skirmishers evading. Here's a simple evasion rule that fixes the issue:
http://impetus.ativiforum.com/t86-adding-evasion-to-basic-impetus
1ngram wrote: Adding Evasion to Basic Impetus
The major hole in Basic Impetus is Evasion. I'm fed up with the number of times a passerby at the club has snorted in derision as my Parthian light horse get caught by advancing enemy foot getting a back to back move, usually adding the comment, "in real life they would have scampered away easily" True! So we have added evasion rules to BI. Here they are:
1. Evasion is a move in Basic Impetus available to any friendly skirmisher or light horse unit when an enemy unit able to charge declares a charge move which would result in the skirmisher or light horse unit being contacted to the front. Charges to the rear or flank may not be evaded.
2. Such a friendly unit with an impetus value of its own may choose to evade or stand its ground. Any such unit with no impetus value must evade.
3. An evade move is a full move directly to the rear ending up facing the same way. If a friendly unit is interpenetrated then the evading unit may halt immediately behind the interpenetrated unit if it wishes or continue to make a full move. If the interpenetrating unit ends its move still interpenetrating it may be moved further to clear the friendly interpenetrated unit. If this interpenetrated unit itself subsequently evades then the previously interpenetrating unit may not evade a second time in this move.
4 If any evading unit is contacted at the end of its move it must fight.
5. Units declaring a charge which would contact a unit which can and does decide to evade may halt after a normal move if it would have contacted the evading unit within that distance if the evading unit had not evaded, or it may roll to extend its charge move. If it does so and does not make contact with an enemy unit it will end its move disordered. If it halted after a normal move it will not be disordered. If after either move it makes contact with an enemy unit it must fight it.
Automatically Appended Next Post: The other interesting thing about Sengoku era warfare, is that unit types were often not brigaded together like in other places. Ashigaru arquebusiers would often have archers right in their formation providing some fire while they load. A given Samurai wouldn't necessarily form up with a hundred other Samurai, but would fight with his personal retinue, so there might be Ashigaru spearmen with him. So when you're making an army, you have surprising freedom in terms of how you array your miniatures. I'd recommend whatever the formation is in terms of the rules, that should be the obviously predominant miniature type.
Here's a cool thread on the topic:
http://theminiaturespage.com/boards/msg.mv?id=277195
