If they follow the same formula of Shogun 2 Vanilla then that is a good start, however :
- Don't release a game with 1/4 of the variation of a total war game 8 years ago and then charge your audience for separate factions / units / battles
- Don't put so much bullshit mechanics in such as super cavalry. Cavalry were not tanks until late middle ages earlier, but cavalry could often take on infantry units head on no problem in the game.
- Don't give one faction everything, romans did not have heavy cavalry and their archers were not amazing, so lets not have that again.
- Make some attempt to produce units that remotely resemble units from the past.
- Morale needs a fix as barbarians were not absolute cowards who just gave up after a bit of a slap.
- Make sea battles actually interesting, rather than a 20 minute stroll up to other ships only for them to spontaneously combust (rome should have the trireme warfare early on which could potentially be hilarious)
As the campaign map goes, shogun 2 did really well so good.