If you are suggesting that the bigger the guy is then it naturally figures that he must be tougher in any way be it physical or mental, I can't buy that one at all. That old expression ain't the size of the dog that is in the fight that matters it is the size of the fight that is in the dog really does ring true.
Now if the suggestion is that we aren't sending really anybody to the plate that just looks a little intimidating from a pitcher's perspective, you might be on to something. We have a whole bunch of potentially good little hitters. With Ortiz, even when he was a little off, pitchers knew that any mistake could cost them dearly. I don't think that anybody is intimidated by this group to feel the need to pitch around anybody. Napoli or Encarnarcion regardless of how they are playing at least give the impression that they can still change the complexion of a game with one swing. As in something other than a single or a double.