I've run a good amount of LI and I've found that guards tend to take more driving layups than inside shots. While layups do depend on IS, I believe they are more dependant on driving. IS is always good for a guard, but I believe that an atrocious won't harm a guard too much. also in inside offenses your guards will take a decent amount of mid range jumpers but not at the level of a motion or RnG. So the SG with 1 IS but better PA and OD will perform much better but will however be much more expensive (I'm assuming) unless the other guard is better in the other skills.