Do you mean the "Commanders" ability ? Those passive buffs you can select for your whole army to have ?
(darmn, talking all C&C Generals style here.... for the Union ! *Rise of the Reds mod = 2 new armies, Soviets simillar to RA2 and European Defense Alliance* .... yep doing a shameless advertisement for no reason ).
Any one care to explain a bit ? As this is also a new mechanic and while it has been mentioned before due to some 20% damage buff or something the post has not been that elaborate to serve as a proper explanation.