How do you differentiate product from portfolio marketing?

We did more portfolio marketing at Cisco/Juniper where we had many "cybersecurity" problems, whereas in early-stage start-ups and fewer product companies I feel it's more classic product marketing.

Portfolio is often more solution or suite level marketing. Strategy is almost business like (done at a higher level with more business level KPIs). You can use a portfolio (like a bundle) to give an individual product an advantage. 

Product marketing has more direct competitive elements.

Other things like GTM level recommendations can be done across both.