The finish swivel may very likely be the source of your grief.
Mr. Kelley put it this way:
"The weak and timid slice tendency of the underswivel is more prevalent than overswivelling with its draw tendency. But the correct swivel is strong, complete, smooth and rhythmic and leads to full power."
A confirmation that golf is such a strange game to most of us!
I went to hitting from swingin and got just opposite results!
Longer with long irons and same/longer with shorts. Maybe I was performing swinging poorly! 4 iron from 175/180 to 195 but more predictable flight. Maybe coming from swinging I swivel more than you...but more likely to shank than before!
good luck to both of us!