If you want to add IS and ID to your guards you have 2 options: either you want fast results, in which case you can best have them play in the scrimmage at the C spot and train C on those skills.
Or, if you want to develop more players slow but steady in ID and IS, you can have them play at SF and train 3 positions in ID and IS.
They are not your friends; they dispise you. I am the only one you can count on. Trust me.