I disagree as the lore states Impererials are more charismatic.
True, the Voice of the Emperor power certainly attests to that, but don't you think their charisma has taken a hit since the Empire dissolved? People used to respect them because they were powerful, but they lack that edge now. Perhaps they're just naturally better speakers than the Bretons though.
Really? English and French people have nothing to do with each other. Nothing at all.
"Better" hair? "Better" Skin? What?
Both the English and French are stereotypically viewed as charismatic, romantic, refined and fairly haughty. These qualities fit the Bretons well. Admittedly, these could also apply to Imperials, which is part of why this problem exists in the first place. The Imperials and the Bretons are both very civilized humans, which makes it difficult to differentiate the two.
By better hair and skin, I mean more stereotypically "regal." Imperials are hard workers, outdoorsmen, and strong fighters, they should be darker and more scarred on average. They should also be more inclined to wear armor and wield strong weapons.
Bretons are more sheltered and delicate. They spend more time studying than working and, as most are mages, they likely don't spend much time outside; thus they should be pale. Being a vain people, they should also spend more time looking after their hair, in contrast to the more rough and unkempt Imperials, and in stark contrast to the brutal Nords. And they'd favor comfortable, silk robes to armor.