Comparing the conclusions drawn based on results from different sizes of Cu clusters we are able to evaluate the limits of our models. We find that Cu-Cu vs Cu-substrate interactions can be a useful indicator of film morphology for small Cu clusters, however they are no longer useful larger models where many more Cu-Cu interactions are present. Given this information, we now know that Cu 4 models are useful for predicting the film morphology and that a large model such as the Cu 29 cluster is best used to confirm results obtained by comparing metal-metal and metal-substrate interactions of smaller clusters. This significantly reduces the computational cost and overall time needed to predict thin film morphology. This provides a rapid method to screen a material selection for specific applications.