the scope of structure being evaluated is of utmost importance
you could evaluate a behaviour in a system which, when evaluated for aggregate net effect upon the largest possible structure of relevance, demonstrates a clear net loss
other evaluations on other structures, or at different temporal scopes, might lead to conclusions indicating or suggestng a net gain
your model needs some type of quantification which examines the relationship of implicated structures 
if you believe there are no more than one structure pertaining to the study in question, then your problem isn't your proposed model
exit