These drones are only provocations and some think it's harmful but it is not. Such incidents don't harm but it only escalates to full blown war. A sneak attack can be done by anyone it is unavoidable thing.
But you have to understand from the conventional military standby Saudi Arabia has almost no threats. Who in the their right mind is gonna march into Saudi Arabia? If escalation comes full blown war happens to the end. They have aerial superiority and could rain hell on the other side.
Saudi Arabia has coaliton and that Coalition is stronger then Iran period. Egypt, UAE, Qatar, Oman, Sudan, Bahrain, Kuwait, Jordan, and Saudi Arabia. Better arms, can mobilize more and endless wealth.
From a military conventional standby not even NATO could penetrate the Saudi coalition if they were to come from the middle head on. Alot of people think provocations are threat they only provide means to escalation and could lead to miscalculation and full frontal war but in essence they are nothing more then that.
They can field large numbers and have modern armies and could withhold a large NATO charge and make it into war of attration. I assure you they don't face such threats outside of NATO or multiplier forces that nobody can field outside of a large alliance group such as NATO or EU