This battle can be compared in some ways to a reverse of the classic bypass of the Maginot Line by the Germans at the beginning of WWII. Oda and Tokugawa have their forces nicely dug in with wooden barriers in place to protect them and sophisticated (for the time) firearms to kill enemies from a distance as they approach the line. Basically, they have a prepared, fortified position with superior firepower at range.
To defeat them, think the same way the Germans did when faced with the elaborately prepared Maginot Line. Again, it was incredibly well dug in, with basically invulnerable gun emplacements that could totally control the direct approach to the Line. Simply charging at it would have resulted in a catastrophe. The Germans simply flanked the line, went around, and attacked from behind.
To the same extent that an enemy is dug in and prepared, they are also nailed down in one spot. The more dug in they are, the less mobile they are. If they are immobile, you should be MORE mobile (paraphrasing Sun Tzu). There is a story from Israel that before the 1956 war, Moshe Dayan was inspecting his troops at the front line with the Egyptians. They proudly showed him an array of elaborate trenches that they had just spent days digging. Dayan is said to have immediately ordered the men to fill them in, saying (again, paraphrasing) "We are outnumbered 6 to 1. If we stay in one place and wait for them, we will lose. The last thing I want my soldiers to be doing is sitting still; I want them charging forward!"
So, Takeda should do this:
Line up some infantry that are not too fast, but carry banners and polearms and whatnot. Make them look like a bigger force by staggering the formation and tying more banners and whatnot to their packs. This infantry has to be brave, because they have a dangerous assignment: they are going to feint right at the center of the enemy forces where they have their barricades set up. It's even better if he has someone who looks like him with his personal banner on a horse with this group, so the enemy thinks this is the main attack. If he wanted to be really tricky, he would give this guy his own personal armor.
The more mobile elements (Mostly cavalry) set out before this attack launches, use cover of darkness, and bypass the wooden screens, coming at the enemy's flank from the top of your map (I assume that's North?). If he has enough men, he can split his force and have the second group do the same thing from the other flank. This is very risky though: I would probably keep all my cavalry together in one huge mob and count on morale and momentum to keep them rolling forward once they overwhelm the northernmost enemy position.
He still has a very tough fight, but if the main bulk of the enemy have already started firing their guns at the decoy force, they aren't going to want to stop doing that when they hear something going on elsewhere. Plus, the guns of the time put up a lot of smoke, which will add to the time it takes for them to figure out that they are shooting at ghosts. Meanwhile, you have to totally destroy the northernmost group, push forward, and hopefully start a rout before the enemy can react. You move to the next small group with your entire force before they can abandon the now useless firing line emplacements, and if you keep up a very fast pace, you may be able to concentrate your forces against a dispersed enemy and take them out piecemeal.