I could be wrong, and I have no concrete evidence to support it, but my best guess is that the UK Op Grange was about plodding through the donkey work that hadn't been done by either exhausted force at the time, and Op PT (with far fewer resources) has been concentrating on the sexual assaults and if there is any link there.
To date, whether there is any connection or not, I still haven't heard that Smellyman or NotSmellyman (if they are not the same in all cases) has been identified.
None of those reported incidents led to an abducted child, which may be why the PJ didn't twig at the time... Why on earth not is beyond me as crimes can escalate in nature, but that seems to have been the state of affairs at the time.
It could turn out that there's no connection, but those families deserve closure as well.
It makes sense to me that the UK side has been drilling down through intensive donkey work to eliminate everyone they can from their end, and that the PT side has been concentrating on the sexual assaults.
My reasoning could be wrong, but that would seem logical to me.