From my own observations, I remain skeptical about Bran Warging any of the undead, including the army. Ever since Bran remote piloted his wolf I've been waiting for his apotheosis. It has never come, and it seems like George R. R. Martin is determined to restrict Bran to a supporting role. His function as a character seems merely expository. Even when he fried Hodor's brain, that was portrayed more as a revelation than a world-changing action. Plus, that one time he green dreamed and encountered the Night King, the Night King pwned him. Bran suddenly understanding his gifts and reshaping the world in a glorious conclusion to the war is something we hope for, as the reader / audience enjoys the underdog hero's full realization of power to vanquish evil. But that doesn't seem to be Martin's style.
