Just to add my 2c, I don't come to the party when someone says 'They all come from the same factory' That's like saying Chum and Pedigree or Optimum are the same because they're all made by masterfoods.
Also, different manufacturers produce products under contract for different companies which might not be affiliated. Same with packaging, just because most milk cartons are made by Visy doesn't mean the milk is.
They might look the same because the companies use the same mould to make the shapes, or they might look entirely different but have the same ingredients.
A friend tried lecturing me on dog food the other day, saying that the only difference in any dog food is water content. I think he was just repeating what someone else had told him and it was obvious he hadn't understood because we were talking about dry food and what he was saying obviously referred to tinned.
Sorry I can't specifically anser your question but looking the same doesn't mean they're the same at all.
