So, under no circumstances can Finnic tribes have lived closer to where Tacitus places the Fenni?
****GK: Ptolemy also places them pretty far north in his chapter on Germania: in Scandia to be precise, north of the Gautae.
Schutte has a theory about the presence of "Finni" below the Goths on the Vistula. He thinks that particular sequence applies to the Baltic coast and was artificially positioned further south. I don't particularly agree with this version, but there is something else of value in his analyses. He has shown that the "Ptolemy constructor" very frequently misplaces or "double places" individual peoples (lots of examples). So independently of the archaeological difficulties, one has to ask why the "Finni" of the Vistula should be exempted from such an interpretation. Have a look at his work and see which other alleged misplacements you would disagree with.*****