I most certainly wouldn't say that for instance taiga and ryoko has the same personality. To a small degree, maybe, but overall, no.
They aren't identical copies, in fact they aren't all that alike at all, just that they are both illustrated in an overly generic hurranimu artstyle.
They aren't identical copies, in fact they aren't all that alike at all, just that they are both illustrated in an overly generic hurranimu artstyle.