I do remember hearing from a Kings and Generals YouTube video on the early Germanic peoples (HIGHLY recommend this channel!) that Roman authors incorrectly linked a few Germanic gods via syncretism, too.
In
Germania, which was a synthesis of secondary sources not supported by any actual field research and yet became a symbol of Germanic nationalism centuries on, Tacitus conflates numerous Germanic deities such as Odin and Thor with broadly similar Roman figures, although some are named individually. While scholars agree on some of the identities, others, such as the goddess he refers to as Isis, are still puzzled over.
