How do we update the order in which the business rules run?

We run code on our leads page that when the page is saved with required fields that aren't populated we have pop-ups to prompt the user to collect the data in sequence. The sequence in which these pop-ups happen appears to be based on the business rules of the page... How do we update the order of the business rules (to force an order update of which fields get marked as required, and in turn the pop-up sequence)?

Thank you for any insight.