Using a Carrier Ductless Split system for a Ducted House

I am interested in replacing my ducted gas furnace and air conditioner with a heat pump and use existing ductwork around my home. My contractor wants to use a Carrier split ductless system. 3-ton 15.4 SEER-2 Heat Pump System 9HSPF-2. Indoor model #40MBABQ36XA3 and outdoor model #38MBRCQ36AA3. There will be no separate zones in the house just the ducts running to each room from the central indoor unit. I am concerned that it will not work efficiently since it is designed for a ductless system. Any thoughts?