I don't think the question is one of whether we have conclusive proof or certainty. I think that it is more a question of probability, and plausibility. I think that a "
hoard" which was an assembled
collection would be assembled different than a regular
hoard would be, and could reflect that difference. So, to me it is plausible that (some) collector
hoards might be recognized as such from their different manner of composition. To me, it is improbable that someone would do that with a
collection, on the other hand I am sure a lot of people's
collections are buried in
banks. End result is that if we actually found a collector's
hoard, we might be able to recognize it. Conversely, if we have not recognize it, a
good chance is that we haven't found one (find, _&_ recognized).
I am not sure whether what I call a "collectors
hoard" is a
hoard proper, just as wishing well might not be considered a
hoard either because of the manner of the
collection. I am not sure.