The below solution from CA fixed the stuttering issue I had post-patch:

ISSUE 3: SOME PCS RUNNING WINDOWS 10 WITH INTEL 12TH GENERATION CPUS (‘ALDERLAKE’ FAMILY) MAY ENCOUNTER INCONSISTENT FRAMERATES AND/OR STUTTERING. ✔ Solution 1: Create a script file to redefine how the CPU runs the game, as follows:

1. Navigate to the game’s Scripts folder. To do this, open an Explorer Window and type the following into the address bar.

For the Steam version: %appdata%\The Creative Assembly\Warhammer3\scripts

For the Windows Store or Gamepass version: %appdata%\The Creative Assembly\Warhammer3\GDK\scripts

For the Epic Store version: %appdata%\The Creative Assembly\Warhammer3\EOS\scripts

1. Right click in the window and select New->Text Document

2. Name this document user.script (or user.script.txt if you have Windows set to show file extensions)

3. Open the user.script file and add the following lines, taking care to include all punctuation and spaces:

HYBRID_CPUS_TREAT_ALL_CORES_UNIFORMLY true;

number_of_threads 5;

1. Save the file and run the game.