I agree with w_alloy. But I'd even go as far as to say your SG should really be a range threat.
If I were picking up a LI SG for $50k, I'd want something like this: 15/11/16/13/15/12-8/7/3/6 $48k/wk (still listed as a PG, though).
But, yeah, don't worry too much about the IS. As long as it's 5+ your guy can make some inside shots and drives. And having the threat outside can do some things for you. It can dissuade opponents from giving you a 2-3 zone. And it can prevent opponent guards from helping down low [although I know this effect is debatable, I would like to think it exists].