Usually I will spin on a bare hook shank. However, talking with Chris Helm, he explained that his "Brassie" hair packers should be used on hair spun on a thread base. The brassie is used to push the thread base not the hair. The thing to remember, though, is that Chris doesn't usually spin deer hair!!! He places the hair around the shank and flairs it. Subtle difference, less movement.

I think the best advice is suck it and see. Find a way that works best for you.
Cheers,
A.