Hi all, just wanna share with you a nice way of having a good start on the Very Hard difficulty level. The Hatakeyama and Mogami are your neighbours when you choose the Date clan.
Follow these and you can get far with the Date on Very Hard. Though be warned, the AI in Shogun 2 does not always act according to plan...
The key is speed and in the end the two outcomes are; Mogami army has to chosen to fight your empty province at Uzen or go back to defend it's capital as you siege it, providing both their cities are captured while this army is in the middle. You'll have more money to train more and better units and upgrades for your cities. The former outcome is most likely to happen based on what I've come across.
1) — First turn upgrade your roads and recruit 2 Yari Ashigaru
2) — Complete the first mission by pairing the 2 Yari you just recruited with the main army and attack the Rebel clan to complete the mission. If your general has retainers that give +2 to happiness this is your chance to raise the tax a higher. You can try and use another turn to get 2 more yari.
3) — With that Army head towards Hatakeyama and stop at the border.
4) — Try and upgrade another building to raise your economy like the trade port. Train 2 more yari and 2 archers and build up a force with the Date clan member remaining in your starting city (I think its your Daimyo or the brother) this is to prepare to attack the Mogami capital as it won't have any much defenders garrisoned.
5) — At this step there are 2 ways you can get 4 regions under your control by 1550. Hatakeyma will accept 5 turns for military access if you offer the same in return.
After step 5 you have a choice to either take them on which you can win by auto resolving - or, if you are lucky, the army that is supposed to guard the city is attacking the Ashima. This is your chance to take their city. If you don't like that option pass the Hatakeyama city, then travel past the mountains and capture Uzen it will not be heavily defended and an auto resolve will surely win the battle for you.
If you are quick enough you won't have Mogami threatening your capital but if they do try and get your capital you do have forces garrisoned from step 4
From here the main Mogami army might approach to retake Uzen. You will send your other army garrisoned in your Capital to take Mogami Capital which is ripe for the taking in 2-3 turns (if you've upgraded roads and if you have level 2/3 strategist skills on your General it helps).
The Date clan member in your capital is able to reach the Mogami capital quickly in 2-3 turns. The settlement should be easy to capture and the main Mogami army that is stuck between its Capital and their former minor city Uzen will rebel. Your best option is turn Mogami into a vassal which gives you 1 unit and causes the main Mogami army that was in the province will vanish or some small force will be left behind.
When the former capital of the Mogami is happy with just your general or a yari garrisoned bring that army down south to your Hayakeyama city to defend it or strengthen it with more yari and take head towards the Mogami army that is in your Uzen province.
Depending how it went and how the other clans have responded, generally around 1548-1550 you should already have 4 of the victory regions for the short campaign win in record time. From around 1552 onwards you should be able to find it easier to conquer the regions to the south.
Going further South towards the Hojo Capital you should see very little resistance, your main army in this section can capture 4 more regions by 1555. Giving you a grand total of 10-11.
Alternatively, you can try heading West where Kozuke is potentially an easy capture, but this will likely put you in conflict with the Takeda and/or Uesugi sooner rather than later.
And that's it for this guide! Those are the steps that worked for me most of the time and gave me an excellent foundation for me to become Shogun.
Extra tip 1: As all the above is going on, ensure you have had your port upgradedto be able to build trade ships so you can acquire the trade post of Iron to the north of your starting region. Place a handful of Trade Ships on that and you'll earn a nice extra income.
Extra tip 2: Fukishima; it will most likely be controlled by Ashina or Hatakeyama. If you are quick you can take this stronghold surprisingly quick with the same army that took Uzen. This region should upgraded quickly and makes an excellent military stronghold as this is perfectly central to your 4 regions north and what ever direction you will conquer in the south.
Extra tip 3: If you can foster good relations with the Takeda, even if they do not share borders with you, this will keep other minor clans near Kozuke and beyond distracted so you can focus your forces on expansion down south.
By following the above steps by 1555 I had 11 regions and earning 5000 to 6000 Koku per turn. I took many regions quickly to the south reaching near the Hojo capital. I lost some key battles and surprisingly the AI's resistance and combined strength of Hojo and Imagawa is very challenging, so beware!
Finally, good luck in your Very Hard Date campaigns!