In Ralph’s original Playability Factor book, “The Maltby Playability Factor, Understanding Golf Club Dynamics, Book One Irons” on pages 38-43 Ralph explains why the correction factors are necessary and how they are calculated. Too much information to post here. There are two charts, fig. 1-32 VCG correction Factor and 1-33 for MOI correction factor on those pages. If you do not have that book or can not find these, I will see if I can get them posted. They are not currently on the website.
Basically the VCG correction factor penalizes VCG locations for each .001″ the vertical cg is above .840″. How much depends on how high the VCG is. MOI correction factor is used to account for those clubs that may have a high MOI, but have a high cg location. You can award an iron design for having a high MOI if the VCG is also high. However, if you have a high MOI and a lower vcg, you can reward the design by adding points to it. The higher the MOI coupled with a Lower cg is GOOD MOI. Higher MOI coupled with Higher cg is BAD MOI.
Hope this helps and I will work on getting the charts on the site.