You can indeed kite him out of a gas-filled room - but at high GRs when the clouds are burning you down in seconds, reacting fast enough to do so from the center of his mass can be tricky. But worse still is that every second you're whirling away from him and not making contact, your DPS is sharply reduced.
Compare to Strafe, which can do the same thing, but while still shooting him the entire time and keeping RoV falling overhead. Nats also has Smoke Screen as a flat-out immunity button + speed boost, and can even be spammed in an emergency.
These move randomly and don't do as much damage as the WW itself, especially if the boss is outside your BotT radius (which, as we established above, is going to happen more frequently than you think due to the need to kite.) Nats meanwhile can run a cold rune or Thrill passive and have 100% uptime on their gem.
At T7 or lower, you can clear efficiently just with your 6pc - you can even run yellows beside that and still do well. Adding Sage's shouldn't change your clear speed, but will greatly increase your haul. T8 meanwhile is the first tier where you can start getting double breaths, and even then the odds are minuscule.