The most critical aspect of any trainer is whether it actually launches without crashing the game. Build 5934 is the final official patch for Shogun 2, meaning many older trainers for v1.0 or v1.1 are obsolete.
Many antivirus programs flag trainers as "false positives" because they inject code into a running game. You may need to add an exception for the trainer.
If you're looking for a instead of a standalone trainer? Total War: SHOGUN 2 General Discussions - Steam Community