In Episode 4:
* <PERSON> was flying in a straight line at a steady speed and too far away to represent an immediate threat to the men on the ships. This is a best case scenario for <PERSON>'s men being able to hit the dragon. Notice that once <PERSON> and <PERSON> were aware of them and moving in a less regular pattern they could not hit them.
* The scene at the end with <PERSON> was under a flag of truce, <PERSON>'s token gesture of giving <PERSON> a chance to surrender without bloodshed. While very, very angry, <PERSON> was smart enough to wait for the rest of the army to arrive.
In Episode 5:
When <PERSON> and <PERSON> attack the Iron Fleet and King's Landing, they cannot be hit by the Scorpions. The reason they cannot be hit is that <PERSON>'s updated weapons are great naval weapons but absolutely terrible anti-aircraft weapons. 516
Far worse than the smaller design that <PERSON> used to injure <PERSON> last season.
<PERSON> was able to aim and fire the weapon by himself. The newer designs are much stronger but they are too large for a single person to move while aiming.
On <PERSON>'s ships the person who is sighting and firing is sitting in a little chair at the back and is completely unable to actually aim the thing. There is a pair of crew-men at the rear moving a large handlebar around to try sighting it.
The scorpions on the walls are worse. They don't even have a guy in a chair to see how they are aiming. The guy in charge is standing in front and to the side while giving commands. They would be lucky to hit a slow moving boat.
It was not shown in the episode, but a realistic version of aiming at a dragon that is swooping, soaring, zigging, zagging, and filling the crews with a rational fear of dying would have the guy at the rear yelling "up, up, up, down, up, left, left, my left dammit, back to the right, right, right, right, down, fire, we missed, it's coming our way!, AAAAHHHHH!" 516