They way they have it set up is not very good, that's why people have been confused on this issue for the past year.
With run/pass, the more the bar goes to the left the more they call run plays. The more they call pass plays. So if you have a coach who has a run/pass rating of 40/60, it means he calls run plays 60% of the time and pass plays 40% of the time. The sliding bar makes sense, but the numbers are what throws everyone off.
As for aggressive/conservative, you take Oregon for instance who runs a lot of quick short passes, well their rating would be 84/16 while a team like Tennessee who throws the ball deep a lot would be along the lines of 30/70.