lol, im the opposite, normally if i join a pf which consist 7/8 or 6/8 of people from the same fc, i will ask them if they're experienced or have studied the fights. If they tell me that they're all good, i would be very glad ( hooray, no need to tutor ), if they're not, well, gotta teach them.
Long story short, make sure every1 shares the same strategy at the beginning of the fight, if not, leave.
however, if they said they're all good but ended up like freshmen, teach them and organize them (if they're willing to learn), but if they start blaming you and you did nothing wrong, just leave, no penalty for premade party :/


PS.I still remember that i led a group of japaneses to clear titan x with auto translate, google translate, and some broken japanese xD