The Aubrac and the Ramagnola are two beef breeds used for completely different reasons. The Aubrac is considered by the Fench to be a 'rustic' beef breed, used in rough, hilly terrain as a tough, low input cow herd to be used with a Charolais bull. They remind me of a beefer Tarentaise with similar fertility udder improvement, and good feet. Growth is similar to a Tarentaise. The calves can have white muzzles, dark eye patches, and black guard hair when crossed with British Breeds. The French consider them to be something like a Galloway or like a ranch type Angus.
The Romagnola is by contrast an Italian Breed that is best used as a terminal cross.They in no way can complete in the maternal or hardiness traits with the Aubrac. They are the shortest and blockiest of the Italian Breeds. They can be very plain cattle with big heads, course confirmation, and plenty of leather on the front ends. They are the third most popular breed in Italy behind the Marchigiana and Chianina respectively. The Marchigiana is light years ahead of the Romagnola for any maternal trait you care to mention and is also better growing. Along with the other Italian Breeds such as the Chianina, they have Shorthorn level problems with genetic defects. When they click with a cow herd they work very well. If you want to use a Romagnola I would also use a some Marchigiana to see what works best. If you intend to keep replacements I would use Marchigiana out of all the Italian breeds.
Aubrac semen or cattle will be much easier to get than the Romagnola or Marchigiana. I think a small association exists for both Italian breeds but will require you to do some diggubg to get semen let alone a bull.