I'm discovering that the the answer to "is it a Linnet or Twite" is pretty much always "It's a Linnet"
I think a possible explanation is the following: most of the times both are easy distinguished by colours alone: linnet has a grey head and warm rufous brown back. While Twites are drabber/colourless brown birds with the right orange-buff face (and breast). This works most times and is one reason, why ID-books put so much weight in this "Twite-coloured-face".
Imagine, you see hundreds of Twites and
adult Linetts and become confident in jizz identification by colour alone.
And then you see your first 1 cy (rarely older) Linnet with very similar warm orange buff tones (and sometimes nearly perfect hues in the supercilium and below eye).
You are puzzled, because you get a Twite-feeling but something seems not quite right.
This answer leaves out:
Twites with drab plumage, lacking the Twite-orange-buff face and throat, but with a bold contrasting white/warm buff wingbar (and sometimes bold white wing patch) as the only contrasting markings.