Can't get my sprite animations to line up perfectly

I have a simple “throwing motion” that happens with just 2 sprites. However, I can’t get the motion to look perfect because when the sprites arm is extended in the second sprite, it moves the entire sprite every so slightly and they don’t line up perfectly. I just want it to stay still and have the arm move. It’s driving me crazy, i’ve tried both exporting the sprites from inkscape and AI but no matter what, I cant get them lined up properly. I’ve also tried editing the pivot but i still can’t get it perfect! please someone help me!

example video - YouTube

hey ;
the sprite size are the same ?

and can i see the code and some screen shots;

looks like the scale is changing of the other sprite