Although Shogun 2 and Fall of the Samurai are IMO the best historical Total War games yet released there are some significant bugs in the game and this is a shameful display because justice should be done to honour the greatness of your creation.

Most notably there is a bug in battle which causes units to stop responding or moving, especially in large scale siege battles. This is extremely frustrating because it can cause the defender to lose the battle or suffer greater casualties than otherwise.

Some other bugs/quality of life issues:
In the faction selection screen, the "daimyo" character that appears for each faction does not fit inside the designated UI on high resolutions. The text on this screen as well as in game is extremely small. This is particularly more pronounced in the FOTS faction selection. UI adjustment setting akin to what we have in Warhammer required.

There are well known instances of artillery being invincible against melee attacks particularly when the melee approaches from the front of the artillery in FOTS.

During naval battles in FOTS or with Nanban ships in S2, the player can fire at enemy ships and then switch to manual fire and instantly get a second volley off in quick succession.

Warrior Nuns appeared on the Ikko Ikki DLC promotional material yet cannot be recruited by Ikko Ikki in campaign.

The tech tree unlocks the Spear Square ability but this ability is only granted to the Yari Hero despite it being implied that Yari Samurai and (probably) Bulletproof Samurai can use these abilities.

Trade Ship crews consist of men dressed as samurai, but trade ships would've been operated by non-combatants.

Uesugi are said to have a higher income from trade tariffs. In actuality, no bonus is given in game.

The retainer which grants bonus to accuracy for samurai does not grant this bonus to Bow Ronin, Daikyu Samurai or Hattori Bow Samurai.

The retainer which grants bonus to accuracy for all bow units does not grant this bonus to the above 3 units as well as Bow Cavalry, Hattori Bandits, Takeda Bow Cavalry, Bow Ashigaru Garrison, or Bow Cavalry Hero.

There's also a bunch of other retainers which don't provide the specified bonus to all the units that they are supposed to apply to.

Occasionally during and after battle, units can be damaged by routing units and score kills.

Portuguese Tercios speak Japanese, instead of Portuguese.

The attacker's deployment zone in ambush battles is too far away from the defender's deployment zone. This means that the defender has consistently more than adequate time to form up and defend well.

The May 2023 patch negatively affected the appearance of minimap/load screen map topography. Previously, geographical undulations were clearly visible, but now the map is darkened and this definition is much worse.

It was not mentioned here before but also fix regular kisho ninja stats in Shogun 2. They are superior(with no reason) against Hattori/Tokugawa kisho ninjas. Some patch long time before broke their stats as regular kisho ninjas had 14/20/8/2 attack/charge/defence/ammo stats when the game was released vs hattori/tokugawa whos have 15/22/10/2 stats to this day. One faulty patch gived regular kisho ninja same stats as hattori/tokugawa except ammo - regular kishos have 11 now which made them hardly superior against special kishos ninja of hattori/tokugawa clans. And hattori/tokugawa clans were designed to had far better ninjas than others.