Ratings Conundrum
 

This is a comparison between two defencemen in a fictional save I've been playing. One is a 3.5* defensive defenceman, the other a 5* two-way defenceman. Can you tell which is which? Seems to me there's little to separate their role definitions. They both seem two-way to me. At this point, should one consider changing role? If so, what effect will that have on the player who gets changed? Just when I think I have a handle on understanding things...

Physical and Mental ratings will have an effect on ratings and roles as well
(I know, it's confusing)