We might if all UK, Canadian, etc currency was "published" in the US, which it ain't. To my mind, the sole factor in classifying pence variants as variants is their relationship to the standard US copies, eg: they were all printed, published, piled up & pushed out as one lot intended for a number of destinations, one of which just happened to be another Anglophone country (or 3). The "vary" part of variant in the case of pence variants only really relates to the indicia. The indicia for all of them has the price in US currency, but the cover price varies in that it is in UK currency.