Protecting it from what though?
 
	 
 
	If the brute can already adequately protect the team, how is increasing the Tankers protectiveness but not damage going to solve the overlap?
 
	 
 
	At least with the bigger AOEs etc, the tank will find it easier to grab aggro in situations where the baddies are more spread out.  Which is a lot rougher on teams than them clustered around the brute/tank. 
 
	 
 
	Then of course throw in that at level 50 most teams need no protection 90% of the time, but the tanker still needs to be able to play ..