It never dropped advanced thread once for me, before 3.0 you could get it and, the Strong Approaching on the hardest difficulty seemed way easier than these "expert" ones, which drop less (not counting group contributions/victories) even if they're harder, before we could also get coupons in group base from doing those group fights, forgot how they're called.

Those coupons we got there for reaching top spots actually helped us during events when we needed just that 25 extra coupons to get one more fragment for a ninja for example.