Although I'm politically neutral between Saudis and Iranians but when it comes to military view there is no doubt Iran is much stronger in fighting wars and conflicts and It doesn't have to be superiority of weapons
The Arabs lack courage and they always need someone to be at frontline for them. Whether it is Arab-Israel War, in which they loose to a tiny country surrounded by all 22 of them, the siege of Mecca by a few terrorists, the Gulf War between Iraq and Iran, the Bahrain sunni-sunni conflict, Syria War, Libya War, the Yemen war, etc
In short, you are comparing Persians who have never been ruled, have a history of a massive empires and advancements in science, and technology with a group of Arabs, well, no offence, who were basically camel riding beduins ruled by various tribes and foreigners.