Personal preferences will make you decide.
When I had my D7000, I didn't like or need the wider lens like the Sigma 17-50mm I had, so I sold and bought the Tamron 28-75mm which basically lived on the camera. You can still get these new and they are excellent performers on DX cameras and will cost probably half of the newer VC model.
You are covered with your landscapes with your 11-20mm and the 24-70mm will cover your other uses apart from wildlife, where you usually need longer lenses depending on subjects you cover.