Hey John,
I definitely recommend setting up global forms in your Marketo instance. It makes lead scoring much easier. For example, you could have 1 form for whitepapers, and then use that across all the whitepapers on your website.
The way you do it is using the 'constraint' on the 'fills out form' trigger. By telling Marketo not only the form that was submitted, but also the page it was submitted on, enables it to know that the form is for that specific program.
Hope that answers your question.