I think GS is fine on the defense event. They can't handle Lebron, he does whatever he wants no matter what and who they throw at him. BUT somehow they managed to not let the Cavs score less than 100pts before overtime, which is a good indication for GS. They usually win when opponent score less than 100pts.
GS is struggling in offense because they don't impose their rhythm.
They are thinking too much and play too tight. As a result, they were even missing open look 3s.
Then something happen and it was simply shocking, the cavs were 20pts ahead and suddenly Curry, Lee and co. started to run everywhere, simulating energy to hopefully catch a rhythm and you know the rest, they bang 3s after 3s, steal 1 and came back to 1 point before losing the game.
GS needs a certain type of rhythm, similar to the Spurs when Pop always insist on Pace.
Shooting 3s is about pace. Shooting a static 3 open look is harder (ask JR Smith).
To me, it all comes to this. If GS will manage to enter into some kind of rhythm, they might win the next 3 games (like they did against Memphis). If they don't, I'm very worried for them.