I feel like people think the new guys have more potential just because they have less time in the NBA. Last time I checked, Moore is 21 months older than Avery Bradley.
I have no idea if JJJ will be any good, but I think he brings enough to the table to expect he can play in the NBA. Bradley already has the skill to be an elite defender, and this is more developed than any skill Moore has (or that I have seen in JJJ in my limited watching).
We still have no idea if Moore can do anything in the NBA. A single preseason game against a bad defensive team where he shot 33% (2-6) is hardly overwhelming evidence. Don't let the 2 timely shots fool you.