1-69 is a crapshoot for all tanks. You gain access to different parts of your kit at different levels vs other tanks. But it's over so fast I wouldnt really worry about it. All tanks will survive the road to 70 and mass pulls really depend on a very solid team to do in level capped dungeons. Tank has to be good, healer has to he good, dos have to kill things fast enough. The entire team needs to he on point for mass pulls without the ilvl advantage you suddenly get at lv 50, 60, and 70. It all self corrects kn the end.