Oh my goodness pearsallc , I can't believe I missed your question. (My notifications haven't been working correctly for several weeks now. I'm working with IT to get is fixed.) Sorry for the delay. Maybe you already figured out something for this question, but I'll throw out some info, just in case. 

I believe we can setup a rule in the "RLC Custom DU Validation Rules" aux table that would do this. I'll have to try it out to verify. But, this table checks the customized rules during the validation process. From the screen print above, it looks like the validation process is already catching the problem with the errors in yellow. If validation is already catching the issue, I don't know if added another rule will help. Is there something wrong with the check as it works today?

Note: I'm turning on notifications for this topic so I should get your reply.

I have had a few instances where the developer was able to request the install of the release package with fixing everything for the processes to run, except that there were no versions linked to the process. They added the version to the deployment units, but did not link the version to the deployment task. 

I have not been able to figure out how to add the rlc custom du validation rules. the documentation, at least the last time I read it, was not very helpful here.