The paradox with most passionate fan bases (not just our own) is that they easily rationalize things for themselves but refuse to rationalize for others. We have a very crowded field at the "wing" positions (SG/SF - which is actually the closest IMO in terms of required skills) with JCL, Williams, Pickett, Jordan, DJW, and Kipper. But many fans were making very strong posts rationalizing adding Goodwin AND Lewis on top of that group. So it is OK to add Goodwin, Lewis, or now Wilkes on top of our crowded wing group, because we will use them "flexibly" but others (e.g., IU) won't be able to even though they may have less people at the wing.
Truth is that IU has less of a crowded field at the wings, and OG has been touted as a pretty high draft pick (higher than Hill actually). Some had even hinted that he could have left this year, but there are very good chances he is gone next year. So IU actually needs to recruit the position.
Nobody can be sure about what Crean and recruits have discussed, but if I had to guess, IU is selling more the opportunity to play together at 2-3, than any of Wilkes/Smith moving to the 4. I have seen both, Smith more times, but it is definitely to Smith's best interest to stay more of 2-3 than 3-4.
Having said that, the timing of Smith's announcement is kind of strange IMO. I would have expected that he waited if he knew Wilkes would be coming along.