Olive baguettes - % olives?

Hi,

I'm a relative newcomer here, and this is my first post.

I've been making DonD's Baguettes a l'Ancienne w/cold retardation (ala Gosselin), which is a non-levain bread, these past two weeks, maybe three times.  Anyway my wife had asked me to add olives.  So I chopped up some Kalamatas and added them at the S&F phase.  

I'm happy with the results.  I've not added additional products to my breads up to now, just stuck with the basic fws&y.  So I decided to add about 6% olives based on total dough weight (prior to the olives).  It seems like a bit skimpy now, but being a cautious fellow by nature, I did not want to go for the home run and add so many that I risked ruining the final product. 

My question: Is there any rule of thumb or guideline that I can use to determine what percent of an addition, like these olives, that I can safely add w/o risk of destroying or overwhelming the final product?

As it seems somewhat traditional to add some pics of output, here are the three of the olive baguettes as they cooled down from this morning's bake.  The pre bake weight for each was 235g.

(as an aside, I like 'em dark!)

Thank you,

alan