Pretty sure they are one after another, I think its m20 followed by m33 then followed by g4 war, could be wrong.
Every HSB resets Master lvl wars (and god lvl too), as there are no wars during HSB. So after a HSB ends all the wars starts at the same time. Over time they loose the "harmony" due to some Master level wars sometimes have no entrees, or only from just one faction so they end earlier. (When a war ends from that time there is a 1hr 10min "cooldown" till the next war's 10 min countdown.) So far as I experienced all wars are on the same time by default and every HSB resets their timing making them syncron again. So mainly a day after a HSB is your best chance to able to enter different war brackets as they loose the syncron but they could still fade to one another.