If i put inspiring command on Magog and gave him a power action to turn Oracle's dial, could he use inspiring command if he gains it from Oracle?

You can't assign Inspiring Command to Magog because at the time of assigning it (before the game begins) he doesn't meet the prerequisites.

The only question you need to ask yourself is, Does Magog qualify for Inspiring Command BEFORE putting any other feats on him? There you will find your answer.

You couldn't give Magog Inspiring Command in the first place; he doesn't meet any of the prerquisites (Leadership or Master Mind).

However, if you put Inspiring Command on a character that did meet the prerequisites, but didn't have the prerequisites on the first click (like, say, Loki), then yes you could give the character a power action to spin Oracle's dial to Leadership and the character could use Inspiring Command with that Leadership.

The reason that I asked is because I noticed on the compatibility list in this section that ICwO works with Brilliant Tactician. I figured if ICWO worked for that one, it could work for Inspiring Command as well.

ICWO only works with Brilliant Tactician if the character already meets the prerequistes. ICWO is a good way to give a character, like Loki, a chance to use BT right away (normally, Loki does not get Perlex until about mid-dial). The character must still meet the prerequisites all on its own, though, to be assigned a feat (so you can't use ICWO to give BT to someone with only Perplex, or only Outwit, like Gambit).