They could easily pass for C.quadrivirgatus to those who don't place much interest in the genus. The C. variegatus are the same length but stand out with enlarged tubercles all over the body (back) not seen in other similar sized/color species. They also seem to be a little stockier in build. The mainland C. quadrivirgatus come in listed as C. pubisulcus, but that species is endemic to Borneo. With the confusion of this genus, I can see the mistake happening.
Side note...one reason I think they list them as pubisulcus is they don't have the typical stripes describing quadrivirgatus, so assume they are the other similar species, but I have found the longitudinal lines are only constant in the Borneo populations and not in the mainland forms commonly imported.