Mentor and Accelerate Crew Training dont seem to do anything...

PanzerXO, on Aug 01 2012 - 17:48, said: I have an elite tank with the commander training Mentor (50%).  According to the Wiki each of my crew members should get an additional 5% experience from the commander's Mentor skill and the lowest trained member should be receiving double the training exp. due to the tank being elite.
You would think that my crew's skill advancement would be higher than my commander's after a while.  But they are not.  They are within 1% of each other.
Admittedly, the average Exp. per battle for a Tier V tank is low... but come on.
Is there any real benefit for checking Accelerate crew training or the Mentor skill at lower tiers?