The general rule for training Inside skills is to train Inside Shot first, then Inside Defense, then rebounding /shot blocking. For instance if a player has prominent inside shot and respectable inside defense then the inside defense will train faster than it would have if both of them were at the same skill level.
It depends what you want to punt.SB is the fastest training of all inside skills, therefore it would makes sense to train it first, especially if you plan to punt IS. IS on the other hand can be trained with 1v1 and JS so it can be trained with outside skills more than any other inside skill (the only other is ID if you train OD) AND most notably gains speed from JS.Between ID and IS and ID and SB, as a general rule it's a good idea to take Coach Parrot track the sublevels and check which one trains faster. Even though SB trains faster than ID, at some point the positive elastic effect of SB on ID will be strong enough for ID to overtake SB in speed.