The majority of Iran's inhabitants are Persian. Persians are of a different stock than Arabs. Germany and Poland border one another, but most Germans are of Teutonic stock while most Poles are of Slavic stock. Of course, considering the fact that the two countries have bordered one another since the inception of those identities, it only stands to reason that there has been a certain degree of intermingling and crossover betwixt the two, but overall, ethnic Germans are still predominantly Teutonic and ethnic Poles are still predominantly Slavic. The situation is very much the same when it comes to Iran and its Arab neighbours.
Iran is one of the oldest countries in the world. The Persian Empire was far larger than Iran is today, but Iran has occupied its current borders for a very, very long time. There are people of Persian, Arab, Kurdish and Turkic descent in Iran, as well as people of many other ethnicities, such as some of the tribes found across the border in the Central Asian republics and those in Afghanistan. So nobody really knows just how many Iranians have some Arab blood today. That's not something that could ever be determined with any degree of accuracy.
While many people - especially Americans for whom genealogy and identity is an obsession, often go on about the various ethnic identities of Europe, the truth is that Europe has seen a great deal of intermixing over the centuries. The Iberian Peninsula is an interesting case because of its unique position at the very periphery of Continental Europe. Various waves of Roman, North African, Mediterranean and other European peoples left an impact on the area. The Moors and the Celts and the Romans all contributed to the cultural, linguistic and genealogical dynamic of Spain and Portugal.
The same can be said of Italy. Many people came from elsewhere in the Mediterranean, Asia Minor, North Africa and other parts of Europe and Asia to help shape Italy.
In terms of the grand scheme of things, the Moors and other North African and Muslim peoples did not have anywhere near as much of an effect on Iberia as did some of the other people who contributed to its history and culture. The Muslims were driven out in a relatively short amount of time by historical standards. For example, Muslim influence is far, far stronger in the Balkans and its influence much more long-lasting than it has proven to be in Iberia.
People have always migrated from one place to another. They moved from one place to another for the same reasons people do today - to seek a better life or because they are compelled to do so for some set of circumstances... Many Dutch emigrated to Norway, many English emigrated to The Netherlands, many French emigrated to England, many English people emigrated to various parts of the world such as the US, Canada, Australia, New Zealand, South Africa and so on... This is nothing new.
The answer to your question is "No, it isn't." Because Persians and Arabs share a common border, they bear many more similarities to one another in nearly every possible category than to Arabs and Iberians - culturally, linguistically, the list goes on and on. Arabs and Iranians share the same religion, though there are wide divides between various sects, just as much of Northern Europe is Protestant, much of Southern Europe is Catholic and much of Eastern Europe is Orthodox.
That's the best answer you're going to get.