Interesting and clever tactic. But begs some questions of, how did they achieve that. I would assume the Moskva must've been pretty close to some land for that to be possible because drones don't exactly have ranges of hundreds of miles - or fly that fast - and seeing as you'd have to have the drone approach the ship from the opposite side of the ship to the missiles, that means that either the drone or the missiles would need to take a very roundabout route to get to the ship. Would seem like some quite tricky logistics to pull off.
The ship was around 60 miles offshore when struck. The type of drone in question has a range of over 3000 miles, you did manage to get the bit right about it not being fast though.