When I reintegrate a hen after a long absence, I put them into an extra large covered wire dog crate in my covered run along with their own food and water so they can do look-no-touch with the other chickens for a few weeks or up to a month. Lots of fighting the cage, and then eventually they get used to each other. There will still be pecking order fights once they're really face to face, but it seems to take the edge off. Sorry you had a poor reintroduction. Sometimes it goes fine, and other times it doesn't. Depends on a lot of factors and the chickens involved.
Sorry they scalped your Silkie. Nuthatched is correct, she'll heal up in about a month and you'd never know she was injured. I'd do a longer look-no-touch period on your next reintroduction. For minor wounds, I use Blu-kote to turn them from red to purple/blue so the bird can stay with the flock whenever possible, in order to avoid reintroductions. However, sometimes removal and later reintroduction is the best choice.
