A different approach has to be taken for Legendary, I think.
With Legendary, the AI has much much larger armies in the beginning, and clans become more powerful (absorbing smaller ones) much quicker. You must thus use a lot of diplomacy and deceit.
You have to produce a mix of both katana and ashigaru to stay in competition, though katana become quite useful in ambushes.
On Legendary, there is no slo-mo, so against a large army I have to wait in ambush for the Ito army to come along. I concentrated first on Mastery of Arts to get Terrace technology (because economy is more important in legendary at first) and then focused on morale.
You often have to detach your daimyo from an army in the beginning in order to ensure your general advances in rank -- because you need a two-star general in the very early game as Military Advisor to boost your replenishment rate.
After capturing Osumi, I build up economy and my forces and wait for the Ito to besiege my city. After defeating their assault (the siege is actually difficult), I can capture their last province with little difficulty. I make them a vassal as a buffer against the northern provinces.
Note at this point your profit stream is 500-600+ generally.
Sagara declares war on me. It chose to attack me directly rather than go after my vassal (which was still weak), which met my army lying in ambush near the bridge. Following their defeat, you capture their capital province which is quite rich (compared to the others), allowing you to expand your army. Sagara will probably have conquered that other province north of Higa, but they will sue for peace and you can make them a vassal. (Note that "fragile" or "weak" clans are still quite strong on Legendary.)
Maintain peace with the Shoni, and with luck they'll go off and invade Honshu through the land bridge (causing headaches for the Kikkawa and Takaoka and the like). Wait for them to conquer 2-3 provinces on Honshu. Their rich heartland will be remain lightly defended and then you strike. You can easily capture their two other provinces (very rich) in the next two turns, and meet their monstrous revenge army by the land bridge or by your castle. After defeating that army the Shoni will be caught between you and the Takaoka.
At some point the Ito might rebel as well (in Legendary, your vassals are less forgiving of past offences), but only if you let them slip into hostile. After defeating the Shoni (I annexed the Sagara amicably), you might re-conquer the Ito, but only for good. I suggest allowing them to be vassal in the first place because at first they are a critical buffer against the Sagara and the Shoni, and this buffer is immensely important on Legendary.
The middle game can proceed from here.
[This message has been edited by Swra Latckretcnin (edited 10-13-2011 @ 06:35 AM).]