I don't bother trying to tell them as I would rather not come across as a cocky little know it all FO (as has been suggested here).
No problems with professional pilots who DO know their stuff
such as yourself. Its the extremely inexperienced cocky little
!!!!s who DON'T know their stuff and honestly think that they
do that are the real problem.
CRM appeared naturally between very capable professionals
well before this classroom course stuff was first brunged up
(around 1990 I believe). Also the FO would've had command
time in something meaningful prior to joining any major at
1500-2000 odd hours, which meant his input did count for
something....esp operational.
And that still holds true. They've learnt what will kill them and
what won't. The rest is just fine tuning