You can rationalize an explanation, but there's no basic storytelling logic there...as you underline yourself with the example of Mick's ninja outfit. The problem with this show is that lack of storytelling logic doesn't rule anything out.
The logic is that Amaya needed to give Mick something as a peace offering to resolve their character conflict, so the ninja outfit he'd already acquired himself wouldn't cut it. Again, much of writing is driven by character, not just plot.