@Joe,
However, I think I went off on a tangent. To your original point, what kind of relationship do you have with your NCOIC? I honestly think it depends on your level (CO, BN, BDE, etc), Branch/MOS, and duty positions (e.g. PL/PSG, Command/1SG, S1/NCOIC, etc.). It also depends on the confidence and trust you have in your NCOIC, their knowledge and experience, as well as their own. So that will determine your relationship. The relationship I had with my PSG on my last deployment was more peer-to-peer, mostly because he was the 1st PSG I had as a PL who had been in the service longer than I had. We mentored each other and were a stronger team because of it.