Just my opinion, but I've never had it "work" when I'd put Silkies with the LF flock. I raise SQ Silkies, but every now & then I fall in love with one that isn't up to par, and keep it for a pet. When I've put them with the LF they always get picked up mercilessly. You definitely have to keep their beards & crests cut short so they can see the other birds coming to attack.....they can't fly away to protect themselves, they're more prone to be killed by a predator while free-ranging....and those LF roo's can really hurt them...
Silkies do very well in confinement; they like small spaces; I'd vote for a small, separate pen all their own....