I've been asking this trough most forums (including the one in Beta section that could be outdated), and all answers differ, so what I know now is:

-Both gives +1 willpower but one is conditioned, so at first sight Independent is more profitable.
-Having Leadership both it seems that doesn't matter at all which trait to pick. (but Independent still looks better).
-Now, people says that Obedient is better because you gain +2 wilpower, others says +3, others says that the +10% armor bonus is bind to the Obedient trait not to Leadership, other sthat Obedient is an 'aura' to your henchmen too, etc, etc, etc,

So, here in Larian, can someone explain well this trait?

If you need to know my build: two Lone Wolves, single player, both with Leadership (apparently is a must-have), and low magic (Man-at-arms & Marksman).