Welcome!
At a global level, his two tests were very similar (global composite scores are nearly identical), which one would expect.
WM: The most striking difference is really in the two measures of working memory, keeping in mind that they do not use the same types of tasks to assess wm.
PS: The two PS measures are less divergent--but again, use different tasks, anyway.
VS/S: these are quite different tasks, as both DAS-II SC tasks are fine-motor in nature, and one has a memory component. Since both instruments find that fine-motor efficiency is a relative weakness, the increased fine-motor load of the DAS-II SC over the WISC-V VSI may explain much of this difference.
It is difficult to say, without additional information, and especially without having seen his performance directly, if these varying results reflect dysregulated attention, but if you find that his attention for low-interest tasks and disorganization are affecting his ability to access major life activities (instruction, demonstration of skills, relationships, self-image), then there is unlikely to be harm in further investigating. But if he appears to be happy, secure, growing, sufficiently challenged without being frustrated, and have a range of healthy, satisfying relationships, then there also may not be a whole lot to be gained from further evaluation.
His ability to focus and perform academically in real life are more important than an atypical or inconsistent set of testing profiles. He obviously is at least in the optimal GT range--whether or not that meets criteria for your local GT program--and cognitively well-equipped to be successful in school.
