i think people shoul understand that the 'traditionalism' of any istrument is largely irrelevant, it is the intrinsic fit of the intrument to the musical style of music favoured by a majority of tune players which matters more.

standsrd tuned guitars tend to define more thirds than is helpful in some forms of trad music, so need to be wielded with care. open tuned guitars and other strummed instruments are intrinsically 'safer' so more likely to be welcomed. (the thirds rule goes for squeezing left hands too).

thus the age of the instument and how its been used in the past is also irrelevant.

the open tuning thing also explains the numbers probkem. five dadgad guitars, a mandocello and an octave mandolin are more likely to gel than two eadgbe guitars who have different ideas about root notes.

its worth noting that a very quiet accompaninment still has a big impact because lower notes are heard differently, even subconsciously, by the tune players.

tom