When Domination was released, the Sons of Bragg were met with a lot of skepticism. The common complaint was that for the same points you could take a minimum unit of Champions with a total of two more melee attacks, 1-3 points more ARM and the ability to benefit from a Fell Caller and Grissel Bloodsong. All of these points are true, which begs the question: Why take the Sons of Bragg? The Sons of Bragg fill a completely different role than Champions. Where Champions are able to take a hit themselves then dish one back out, the Sons of Bragg are best avoiding the hit until they can either launch an alpha strike or provide the counter to a hit that a different unit has just suffered. Additionally, Champions want to be bunched together to benefit from Defensive Line. The Sons of Bragg can take advantage of their large command range and still benefit from their fell calls, allowing them to charge from multiple angles and making it difficult to take all three out at once.
With the right buffs, the Sons of Bragg can mow down enemy infantry, wreck light warjacks and warbeasts and cripple heavy warjacks and warbeasts with average dice rolls. Even without external buffs, Fervor can turn the entire unit into an offensive force to be reckoned with.
