As you have realised, the series was a joint venture, hence why there are differences between cache listing and some of the caches are old caches, renamed to make the series up as they were already in a position for the series.    It took a while to get all the caches in place, so place dates reflect this - I can't see why this is a problem.

Wonder who's going to get the FTF on the Wherigo 

I do hope the series is a good walk and worth doing.