What PMM team sizes and roles have you seen in relation to overall company and sales size, or other markers.

It's difficult to generalize here. You need to first establish the need for product marketing because not every company needs a product marketing function. In my opinion:

Small companies or start-ups (<20M ARR) can delay hiring product marketers if the founders or early marketing employees can perform the job. Once you have happy customers and start seeing competition in your sales cycle then it's time to bring in a product marketer to develop competitive positioning and fine tune the GTM messaging.

As revenue increases you can add experts within the product marketing function based on business need. As you set up a sales function you will need PMM to develop sales enablement material or create thought leadership content (blogs, e-books, whitepapers) to drive brand awareness.

Finally, as revenue approaches 50-100M ARR you will need dedicated resources in product marketing to handle GTM messaging, pricing, sales playbooks, campaign management, content development, analyst relations, product launches and customer advocacy programs such as advisory board or content for user conferences.

In established enterprise companies you see large product marketing teams with multiple people performing the same product marketing function but are distributed by regions. 

This is a great question and certainly varies by industry. In the tech landscape I've seen:

• Series E with a team of 30 product marketers

• Series C with a team of 8 product marketers

• Series B with a team of 3 product marketers

• Series A and Seed with 1 product marketer

and a partridge in a pear tree :)

The delta really lies within GTM motion. Are you a PLG company? You'll likely be more PMM heavy versus Sales-Led company where PMM is not taxed so heavily.