It’s a good theory, but not obvious at all.

- It is not known that that the Romans used knitted clothing. Knitting was invented later.

- Knitting can be done with cheaper, easier to craft tools that are just as effective. Knitting doesn’t explain the cost and skill required to craft the dodecahedrons.

- There is no wear on these dodecahedrons that we’d normally expect from a well-used tool.