I would also say Vlad Tepes is a fabricated persona, but instead of the church, I think Dracula himself created it. I thought that would be good way to help make some sense out of his love story with Lisa as well.
In my head canon, going with IGA's comment about Mathias living peacefully between 1094 - 1476, in order to hide from the Belmonts, Mathias adopts the identity of a local count. His made-up personal name being Vlad. The logic being that if he would just loiter around a cemetery somewhere, stories about a vampire being present would inevitably spread, and would give away his location. Meanwhile, he continues his study into dark magic and grows more powerful. So basically, he would be familiar with the local population as a bit of an eccentric figure, there are all kinds of rumors, people could be afraid of him, and so on, but it's all just hearsay (for now). Isaac also mentioned he "protected the land" in the Curse of Darkness manga, so perhaps Dracula acted as a local authority? But I digress.
So given that Dracula now has a little connection to the human world, this makes his encounter with Lisa more believable, IMO. Later, when all the mysterious monsters show and start attacking people, there are rumors that this Count Dracula figure is behind it all, and he is attributed the nickname "Tepes". Hence, Mathias becomes known as Count Dracula Vlad Tepes.