Naming these early EuroAristo profiles is always a problem. Although the WikiTree standard is to use the names they would have used, this is particularly difficult with early profiles as almost all documents from that period were written in Latin, and there was no consensus about how names should be spelled and even within the same document you can find different variations of the same name.
I'm not sure whether it was a deliberate decision but we mostly don't use the Latin name but the modern version or recognised version of the name, though still retaining differences in modern European languages as appropriate (Henry, Henri, Heinrich, etc).
With Last Name at Birth (LNAB) the preference is to use the dynastic name, but at times when this is unclear, or not known we use the country they ruled. Again this is often the modern version of the country name. Sometimes the LNAB might be Scotland, but the nickname field might have the more correct title, King of the Scots.