looking at general profile V size, I would say the Sovereign class is streamlined enough for slipstream, it has a relatively small forward aspect profile for a ship of it's size and the Achilles has been described as much larger (at least my impression is it's huge).
Galaxy and Nebulas... that's tricky, they're not really "space aerodynamic" like Voyager or the Vesta, but since when has space physics ever reflected the capabilities of a ship? I'd say it's entirely possible the Galaxies and older can't endure slipstream for some other reason, possibly because of the subspace damaging warp tech they were designed for? The newer ships Intrepid and up didn't suffer from these issues.
The idea that the Breen prototype ship being symmetrical may merely be because of how atypical the breen starship superstructures are.