Well keeping aggro on WAR is bit challenging because TP is everything for a WAR. Let assume that you are using the optimum gear at lv 40 range. The best advice I can give is to Tomahawk, overpower x2, heavy swing, skull sunder (2nd target), butcher's block (3rd target),the point is to alternate your enmity combo amongst all targets. If you are not sure if you hold aggro or not just use Overpower. At lv45 you get Steel Cyclone. So you start with Infuriate, Steel Cyclone, Overpower, the rest are focus on building gauge in order to Steel cyclone or use inner beast. Hope this help in a way .