My swing changed over the years as my body changed. My center of gravity changed, especially as I got older, less athletic, less flexible. I used to swing relatively flat, seldom taking a divot with mid-irons and shallow divots with short irons and wedges. My ball flight naturally wasn't nearly as high. But as I got older, heavier and less flexible, my swing became more upright, and my approach angle into the ball was much steeper. On normal dry fairways I didn't have much of an issue. But in wet, soft conditions - I really had to guard against hitting it fat and laying the sod over the ball.
Perhaps that's why I gravitated more toward irons with thicker soles, like the Ping G-series irons I enjoyed playing. No matter the conditions, they always seemed to work out okay. Thin-sole irons (for me) were chunk-city. They just didn't fit my swing type.
PS - I've also learned the hard way about being 'fitted' for new irons on hitting mats. I know that in the winter months it's commonly the only offering at many local driving ranges, and it's a necessary evil. But all it's ever done for me in the long run was give me bouts of tendonitis. Some of the newer technology composite fibers are nicer and lessen the shock, but still - a divot offers much more feedback that a mat can never reveal.