It looks like its shooting arm switches depending on the direction it's facing
That's correct, and that is an "issue" in the original pack as well. Fixing this is of course possible but would be quite time-consuming. I am grateful for such a high quality PC at a minimal price, and I think this is an issue that doesn't affect the overall result much.
I manage to get around and draw proper left and right sprites during the development of my own game SODHARA, I will contact ansimuz to add those to his collection if he agrees.