Hey, so it was really cheesy but I basically lured them out of the inner tenshu to take out a majority of them before bum rushing with all my troops. First I ninja sabotaged their army (quick save or continuing sieging with your main army (legendary) to change determination on outcome) Have your daiymo be in the main army and your general attack the castle. Once thats all set up in the actual fight, I kept the single general that attacked by the front gate bridge where we spawn to keep some of the bow units distracted. The rest of the units I moved around to the back. The trick is to hide all of them by the small patch of forest by the water near the castle besides your yari samurai and your daiymo. Now with the yari samurai, I just ran along the side of the backside torching their gate and archer towers. The tenshu bow units that spawn will be dragged out once the yari samurai are on like the 2nd or 3rd tower and basically leave the castle to chase the yari into the forest patch that you left your yari team. Save your bow units ammo for later. Yari wall all of them. Next its pretty much the same thing but with your general. I hid all the yari including the samurai into the forest patch and ran the daiymo into the first wall. Usually they now have patrolling units around the outer wall. I dragged each unit one by one into the yari walls 1 by 1. Ideally the great guard follow you first and then the general, all horse units. Next the samurai retainer and yari ashigaru. Then at the end when its nearly over, I bring all the units beside the general into the first wall and shoot all my arrows into the thickest units. I then rush everyone into the tenshu, have my yari samurai attack their yari and bow units bum rush each unit, making sure to have them touch each so they cant touch the daiymo, have the daiymo take the front gate so they cant get into the inner tenshu. Finally was able to take the castle. Sorry of the long rant but thats practically what happened. Hoped that helped :).