Why are the Latinized/Romanized forms of ancient Greek names more popular?
E.g. Tartarus instead of Tartaros, Daedalus instead of Daidalos, Cerberus instead of Kerberos, Cassandra instead of Kassandra... There are a lot of these names that are more widely used in their Romanized forms. Yet if we talk about mythological names instead the Greek names are more widely used (althrough this was different over 200 years ago)
Presumably for the same reason we say Rome and Florence instead of Roma and Firenze. Just as England has been heavily influenced by French culture, all of Europe has seen things through the prism of the Roman Empire.
“Fiorenza” is an archaic or poetic form of the name in Italian. This version was commonly used in older Italian literature and poetry, including works by Dante Alighieri.