Re: Am I wrong in thinking that if ..
Yeah, drone + engine = horrific catastrophe.
No explosives required, just some additional metal mass in the engine, and ... boom! Adding any kind of projectile weapon to the plane wouldn't do anything good. You also have to account for where those bullets land. However, the airplanes could be outfitted with emergency jamming devices to drop the drone out of the air.
From what it sounds like, though, is that the pilots are not aware at all until it's way too late. You can't do anything when you see the drone within 100ft of the cockpit.