Minorities (Kurds, Arabs, Baluch) exist but are fragmented and isolated through geography. So, there is no large, unified group that Arab states can easily mobilize.
Iran’s geography helps prevent proxy building. Mountains in the west (Zagros). Deserts in central Iran. Strong border control.
So Arab Monarchies rely on economic influence and relationships with USA and covert relationship with Israel to get their dirty business done.
In short, they dont have the capability and means to do it themselves.