It would be true to say that 'neanderthals' (or whatever we're calling it) had more potential in terms of intellectual evolution, since modern day humans have hit a dead end to that quite a while ago.
Disagree on the "dead end" bit.

However, 'dropping a human from a near current time and one from a prehistoric times into the wild', isn't really a relevant question for intelligence.
Since the latter has spent it's entire life doing exactly that, while the prior has spent it's entire life wondering how the remote found it's way to 'x' location.
I hesitate a little on the comparison you're making, but agree on the relevance of the question being asked.