From what I understand, look inside uses mostly driving against OD to find scoring opportunities. This is probably why he can run it effectively with only a PG, SG, and SF. I would think it would be advantageous to run a 3-2 or 1-3-1 to counteract the guards driving.
However, Lealster has a valid point that you should be able to make him pay on offense. While his outside defense will be tough to penetrate and score initially, you should dominate the boards and get many second chance points. A fast paced offense like look inside is definitely a good idea. Shot volume will be the key.