Do u really do the taunt at 2 breaks method? Have 1 tank 4 stack break in normal the 1 OT taunts double attacks. In heroic The OT's switch back and forth as to cycle CDs especially during Feud. So yes in quite a few Guilds a break tank could simply be a DPS tanking chimaeron 5sec swing timer no beath above 10k...id say yes GS can falter as i have seen it happen.