In fact this is exactly how the languages born. Yesterday, hey, we speak catalan, today, hey we can´t speak catalan nomore, this is "valenciano",yesterday hey we are speaking castilian, today, hey, that´s andaluz, yesterday, hey we speak latin, today, hey, this is not latin, this is castilian, yesterday, hey, I´m a monk and I do not understand this book written in Latin, I´m going to write the translation. It´s a percentaje question. When you reach one point after centuries of evolution (point that could get decades), this is nomore a dialect, it´s a different language. I´m in one side of the peninsula,
the next village, I see that there is a different word in his vocabulary
and when I get the other side of the empire, I´m talking in romanian. Yeah, you could call that dialects, ok, but when start them to be called as different languages?. I insist, we are talking about centuries ago, they could be called as dialects, they could underestand themselves, it´s good, I accept that but if the romanic languages born about eight or nine century, it´s difficult to me to think that the mozarabic languages were only one
About latin, no this isn´t exactly how it happens. Yeah, it were two different languages but french and the other romanic languages didn´t exactly born by that and I´m going to gave you one example: the castilian didn´t born because they already get two latins, the castilian born because romans already get two latins and Basque people didn´t speak good Vulgar latin (Yeah, I know, it´s rare, they hardly are the responsible people of spanish born and now they don´t want to be spanish) and I supose that the rest of the so divided peninsula speak their manner of vulgar, we were not SPANISH until the romans, even we weren´t exactly the same as France because in France they were hardly all celts. We only were Iberia because we are a peninsula. Here you could found dozens of tribes of celts, iberians, celtiberians, Basques, germans. Even in ancient times, Hispania were one thing and Gallaecia was another.
About the question of Iran, we are not the sons of a islamic conquer, we are the sons of a Christian "recconquista". If someone is going to put the language, it would be Castile, Portugal or Aragon, NEVER Granada. I´m exactly saying that Iran isn´t a good example because in Iran farsi survived in spite of Islam but here, mozarabic languages survived only by those who were Christians. You only could get an species of farsi if you get Al Andalus thriumphant here and you´ll only get that converting us all so no mozarabic languages at all. If you get here a surviving Al Andalus you´ll still get the arabic as spanish language because we are so different, we are not Iran.