I could be wrong, but I think Odie uses Jamieson's yarn. I don't know enough about the technical aspects of making knitwear to comment further.This is my exact experience with Laurence Odie v. Harley shetlands. I have 5 Odies and 4 Harleys in rotation, and the Harleys are all knit considerably thinner.
Do you have any idea why/how the Harleys are knit thinner than the Odies? I know they all use the same JC Rennie yarn, and the ply looks similar to my eyes. I think the Harleys are knit more “open” but how is this achieved? Less tension on the machine?