A reader named Corujalinda made an interesting comment on the post about the Campolina horse. She said that technically they don't call the distinctive nose of the Campolina a "Roman nose."
A Roman nose (which is nicely called a Ramskopf or "Ram's head" in German) has a curve that starts up between the ears and arches down to the muzzle. The Campolina ideally has a flat forehead, and then an arch beginning just below the eyes and running down to the muzzle. She said she's heard this kind of head simply called "jeitinho Campolina" (Campolina style) or "um nariz bem pronunciado" (a well-pronounced nose).
To clarify, she sent me this Wikicommons photo of a horse with a true Roman nose, and a photo of a good quality Campolina, showing the flat upper forehead and convex lower profile.
Here is the Roman nose:
And here is the ideal Campolina nose: