This is not based on facts, but just my observation. I'm training guards for 4th season now and my three trainees both have high driving (13, 13 and 11) and low IS (2, 2, 2) for my league. They drive a lot in inside tactics, but miss - say - more than half of layups/dunks.
Few weeks ago, I bought a SG with DR 12 and IS 7. Suffice to say, he's around 60-80% when driving to the basket (depends on strength of opponent). And that's all the evidence I need. Next time I'm training JS or 1 on 1, I'm always doing it at SF/PF position.