First off a small disclaimer: I’m currently commenting on features which I’m not directly familiar with myself. I know what they do, but I don’t have personal experience because these are supported by a higher tier license than the one I have.
I don’t know if any plugins are available (never kept up to speed with those) but I think the Impact Analysis tools are what you’re looking for. Although not fully automated (they won’t ‘rate’ one diagram over another) it will give you a good insight overview of a diagrams complexity, the Matrix tool in particular.
Impact Analysis is supported by the Standard version and up.
I hope this can help here.