I don't buy into the claim to beat a moonballer you must moonball. I think the key thing you need to beat them is patience.
It's a good learning process, and I myself used to lose to this one guy who had great strokes but insisted on moonballing instead. After losing two matches to him through frustration I adapted then began beating him. Thing is, it still wasn't much fun so we don't hit anymore but I do thank him for improving my game.
Only issue (and it's quite a big issue
)with the patience approach is it must be allied to consistency, and I'm not sure how much of that 4.0 players have.