Reposting this from elsewhere in these comments because it's about the original post and all the comments as a whole more than it was about the specific thread:
There seem to be two separate arguments running about in all this. One is that the Super Young Team don't act like Japanese people. I don't know enough to know whether that's true or not, but that's certainly a perfectly valid kind of argument to have.
The other argument is that the Super Young Team don't act like the superheroes of Japanese fiction, which I don't find a valid argument. To me, that's like saying a unicorn's horn is the wrong length or that a real ogre wouldn't behave a certain way, or something like that.
Japanese people are real, so of course any story set in the real world or one very much like it, such as the DC universe, should strive to accurately depict them. Japanese superheroes are not real, which means there's no reality for writers to hew to. They can write them as Sentai heroes. They can write them as Liefeld-esque guys with millions of pouches and straps. They can write them as all telepathic. As all non-telepathic. They can write them as all gaining their powers from the same crashed alien vessel. They're all equally valid courses because it's all make-believe.