Recently I noticed that in AC Origins when I go to a dense part of a town/village, my character movement becomes less responsive and I couldn't even walk in the direction I wanted.
After days of trial and error, this is what I did and eliminated the issue completely!
1) Locate your ACOrigins.exe
2) Right-click and from Properties go to Compatibility
3) CHECK "Run as administrator" "Disable full-screen optimization" "Run as Windows 7 compatible"
4) Apply and enjoy the game