IMO, you are over thinking it.
Just decide what you want your asset allocation to be and go from there. Asset allocation is really all that matters anyway.
If you're dead set on "diversifying" between active and passive, merely take 50% of each asset class into active and 50% of each asset class into passive. That is the simplest most straight-forward way to do it.
No offense meant (just in case you don't know), but these are the asset classes:
-large cap growth/value
-mid cap growth/value
This post was edited on 7/17 at 9:20 pm