If they follow the Russian tactics, they will send the drones in to distract the air defense systems and right behind them will be the missiles which are far harder to take out and carry a bigger payload.
It really just depends on how far Iran want to go. The drones will be more of a nuisance, most will be shot down IMO but if they also fire long range missiles also in a co-ordionated attack from all sides this is going to escalate very quickly and may go nuclear. Most Iranian nuclear facilities are in remote areas I believe so they may be nuked.
