Lets take an in-game example.
My last two games, same form, same line-up. The first game I played push the ball, OF was inept(low), the second game (remember: same form, same line-up, not training updates in between) I played Look Inside, OF was awful(low). How come this ain't exactly the same in both games? The same players played. My backups even played less in the 2nd game, so the OF should be higher there.
Maybe you have an explanation for this, because I don't. If only your own players affect the offensive flow than there is something very strange here, since the same players and with the same stats (no training update in between) played.
I'd like to understand the OF as well, but I do believe it isn't only your players skills who have influence on it, there has to be more.
Your PF and C don't have the same passing rating as your guards, correct? :-)
My thinking is that offensive flow is the Hattrick possession of BB. As a consequence, it depends on the tactic used (play inside? If your interior players suck at passing, your OF will drop).
I don't really know how it is calculated... (weighted) sum of passing skills of all players? Ratio between your offense and their defense and vice-versa?