I'm working on a simple thing to try and project 2010 record

So, I figured I'd go with BtB's power rankings as a base line.  But something really jumped out at me.

For offense, it's simple, you use total projected runs when it comes to the bat (wRC).  Same with pitching, total projected runs given up by pitching.

But defense and base running are different.  You're only adding runs based off the average.  So (completely making up numbers), if a team is +10 defensively against the average, and the average is "20 runs", that's then +30 runs defensively. 

Now I understand that for a ranking basis, it doesn't really matter because every team is getting that 20 runs.  But on an individual team scale basis, I'd assume that's a rather big deal. 

Now I understand that you can't actually come up with "total defensive runs" because you can't calculate what the average is, you only know how players to compared to one another.  But then wouldn't that make more sense to then do everything else based off average? 

Or is this something like with Park Factors that I'm missing something obvious?