VA-3 doesn't conform to the Gingles test. When it was first drawn the district court said if doubted that a compact majority BVAP district could be drawn. And that district had a 60% BVAP. They "corrected" that district by removing Portsmouth. It hardly makes a district more compact by removing the largest concentration of blacks, and forcing the district to jump back and forth across the James, and skip Portsmouth, but include parts of Norfolk. In the latest litigation, Virginia claimed they were trying to reduce the number of county splits - but couldn't explain why a majority of the splits were because of VA-3.
I think the Long Island example sounds like a political gerrymander to either help or hurt Peter King.
While the current VA-3 is indeed a monstrosity that ought not be protected, you can make something pretty compact that is black-majority, but which requires double-spanning Richmond and Henrico:
51.8% BVAP.
I'm not even sure how to respond to your thoughts on Long Island, except to cite Emerson's quip about how "a foolish consistency is the hobgoblin of little minds". I mean, have you
seen the current NY-2? Do you have any sense of the history and geography of Long Island? Does
anyone think that the current district (which is, BTW, an R+1 PVI district surrounded by R+2, EVEN, and D+3 districts) was drawn for the purposes of being a gerrymander?
I mean, I respect that this might be a corner case where optimal lines end up being sacrificed for the good of better redistricting everywhere else. But it's a sacrifice all the same.