I have battled on and off with the overswing piece especially with my long irons, personally even a "90% swing" feel didnt work for me, I needed to feel even less, my thought was a "Finau swing" or basically "waist high" and surprisingly what felt waist high to me actually was a normal looking swing length and resulted in very solid iron shots without any distance loss.

I would make sure you get the proper pivot piece fully down too, my overswinging was drastically reduced when my instructor got me to finally start pivoting properly, so it's possible that once you get the pivot piece fully dialed it will make the overswing piece easier to change.
 

I can't speak to the back-swing, because I'm still working on that, myself.  But the hip pivot thing I can.  After reading on another forum a couple extensive threads about the biomechanics of a good swing, and related articles: The penny finally dropped.  This happened post-season.  Then we had a nice day in January where I could throw the mat out back and give it a try.

Holy smokes!  I hit about three dozen balls out into the woods.  Instead of my normal fade or slice, I was now getting a lot of very straight hits.  My misses were draws or hooks.  I think I had only two I hit thin and a couple slices.  And distance?  Wow.  My next door neighbor found one of my balls about 150 yards out.  That's 150 yards out going through trees.

1 hour ago, klineka said:

I have battled on and off with the overswing piece especially with my long irons, personally even a "90% swing" feel didnt work for me, I needed to feel even less, my thought was a "Finau swing" or basically "waist high" and surprisingly what felt waist high to me actually was a normal looking swing length and resulted in very solid iron shots without any distance loss.

I would make sure you get the proper pivot piece fully down too, my overswinging was drastically reduced when my instructor got me to finally start pivoting properly, so it's possible that once you get the pivot piece fully dialed it will make the overswing piece easier to change.
 

Thanks for the response. Yes, I have seen people swear they are waist high and they are so far past. The correct pivot is the starting point for sure and working on anything past that is just a compensation move to correct for a poor pivot. I plan to really nail it down.