I would agree this to be working for dl or edl bosses as it requires low amount of people to kill.I don't think people realize how long windows helps we know top clans will camp but so can small clans, so that's not the reason it is getting people on at that time instead of knowing you need to be there at let's say 3-3:10 you have to be at the ready for three hours to log, so maybe a smaller clan gets lucky and can get people to log faster.
But not for legacys bosses which not only requires tons of time to kill but a lot of Right/high lvl toons to lock.
Having windows as long as the legacy bosses or raid bosses is what gives them a chance to log.
Not a 3hr spawn window.
If a small clan can gather a team n camp for 3hrs so can the dominating one!
If they have a proper known time then the small and the dominating clan can schedule, helping the small clan get a chance at winning locks wid a better team.