Yes, i am not going to take up unnecessary bandwidth by typing things that have already been said, but it is definitely 2 different and not directly related tests, and the key problem is that both check-in staff and some Schengen agents link it into one total test, which gives the wrong result to those close to 10 years from passport issue. Mr Calder makes his living by pointing this out every few weeks.
It is further complicated in that Sweden, Norway and Denmark have a joint rule book which tends to support the one test argument, so easyJet in particular has declined some travel saying "yes we know your passport is OK but we just know the agents there will treat it as too close to expiry".
Passports are currently being issued, as renewals, in under 2 weeks. This probably will creep up to 3 weeks in a month or so, but frankly when one is one is holding a passport with 9 years 6 months from issue date, then it is best to renew. I also "suspect" that that a passport fee rise is coming through.....