How long would it take for a Tallahasse to destroy a Ranger?

Hrmph, I'm too stuck in the mud in the old conventional way of thinking antiship guns have to be on turrets, or be huge missiles.
You mean like the WC2 Concordia's Phase Transit Cannon, which was neither turreted nor a missile? :)
Yes they did - look at the line drawings in Claw Marks. The Phase Transit Cannon, which was so large that it formed the *keel* of the Confederation-class, simply wasn't one of them.
The sprites had no movable parts, but the turrets are supposed to be there. The Broadsword has turrets on WC2 - they don't move, but they are there.