Well, I don't know if this is related but... In the Epsilona Revoluta system, the innermost planet gets pulled from a .29 eccentric orbit to nearly circular by the other planets. I'll have to investigate more. So I think the large mass objects will straighten out (and flatten, apparently) the orbits of the smaller objects. (assuming the larger ones are NOT eccentric and are NOT highly inclined. (Wait, they should be inclined to help the lower mass objects from getting ejected, amrite?)
Did anyone get confused?