OK so lets compare the two designs. One has a pusher, the other does not. But both have tail rotors.
Now about that tail rotor. It is only needed at lower speeds. At high speeds the asymmetry caused by torque at the main shaft can be countered with a small rudder on the vertical stab. So why not put the tail rotor (fan duct in the case of the Bell) on a gimbal so that it can convert to a pusher as the speed increases? Should I call Bell because I hate the thought of Boeing being awarded anything right now.