It's deeper than merely 'polishing up' on manual control. Manual control carries with, especially with the Bus, an inference of OFF NORMAL a/c behaviour, relative to many conditions. Becoming complacent with too much autoflight is not the problem per se. Any rare event needs be addressed by a PILOT who is familiar, stop.
Training, yes, but in with familiarity are many Human attributes that get neglected in the rush to defend a particular format. First things first?
How about confidence? Spatial awareness, this having been seriously challenged in Simulator?
A Type rating as the be all and end all of a career is a dangerous thing. Awarding a type rating to one who is not fluent in Principles takes away the latitude an airman must have to respond intuitively to an emergent event. A human pilot who is without intuition borne of experience makes a (very) poor robot.
The last most egregious example of Airline HUA is the inability of a crew to transition from autopilot to Manual Control.
And that was NOT the result of a lack of "Training" Unusual attitudes.