Actually, other than the first weekend, only AVP is opening initially for those in S&S at Finn's. Dracula Untold does not open until 6:30. However, this past weekend they changed the opening time for TWD to 6:00 which is great except that going through that early messes up the strobe effects for the ending scene.
There was also an adjustment to the opening time for Halloween and that house is now opening immediately when they release S&S.
If you're set on using Finn's for your S&S location, I think you'd be okay doing AVP, getting in line for TWD before the crowds descend and after that heading straight back to Halloween. This SHOULD give you the best chance of minimizing your wait times for the 3 houses that tend to draw the largest crowds. You could try AVP, Halloween and then TWD but I'd be concerned because when the masses start entering the park, most head straight for TWD so I think you'd be more efficient going AVP, TWD, Halloween.