The longer the hosel, the higher and to the heel side the cg usually is, which is not good. The more offset, the higher the longer the rearward cg dimension, which is good. You can have a good rearward cg without a lot of offset and you can have a bad rearward cg location with offset. It simply depends on how the overall mass is distributed. Generally speaking, more offset will improve the rearward cg number. Shorter hosels can give designers the ability to put more mass in good places that can increase the playability. Does in it mean they all do and that all shorter hosel irons will be more playable, no. Longer C-dimensions (horizontal cg location), lower vertical cg, more rearward cg location and higher MOI are all important to the stability of the iron and thus a higher playability / MPF rating.