Personally, I think the defense of doubles ARC 10 is better than that of ARCZ, because ARC 10 is flexible and its head is not heavy. Before Baidu knew the answer, I analyzed the difference between 9900 and ARC 10. ARCZ has a heavier head, faster killing speed and sharper points, but speed is not dominant in passive defense. You can use ARC-Z when you are energetic in singles, and ARC 10 when you are tired. Make sure that Bow Z exerts its power correctly, otherwise it will be difficult to play a high-quality ball.
I hope I can help you.