Question about fudge-making?

I have attempted the "old-fashioned" fudge recipe several times and failed. I have always preferred the taste/texture of this fudge recipe (no evaporated/condensed milk, marshmallow creme, etc. from the Hershey's coacoa tin). Since I have failed at that recipe so many times, though, I have decided to try the one from the marshmallow creme (Fantasy Fudge recipe). I have learned from research not to stir the fudge while it is cooling down from 235 to 110 degrees. This fantasy fudge recipe seems crazy, though, because you stir in the chocolate and marshmallow creme at the end, after it has reached soft ball. Should I let the fudge cool, untouched, until it reaches 110 or should I just follow the recipe and immediately stir in the chocoalte/marshmallow? I know that adding corn syrup in a fudge recipe reduces grittiness. Is this the same purpose the marshmallow creme serves? I think if I knew the purpose the marshmallow creme, I could better understand the recipe. Does anyone know?