I'm going to give this one a thumb's up because I've always thought cross-world hunts should never be allowed. Hunt trains and "reserving" the hunt for it are bad enough, but at least that's people from the server. When you get people on other servers coming to your server warning people against killing a target because the train has "reserved" it for 6 hours in the future, then there's a problem.

I used to happily join Hunts on my server when the word would go out and we'd all gather. There were early pullers here and there, but for the most part everyone tried to wait for as many people as possible. I barely bother with Hunts anymore, except the solo ones, because the assembly line scheduled Hunts killed the former spontaneity and that has only gotten worse since you can get an entire train of people not even from your server coming to kill your server's targets and telling you you have no right to them.

If SE isn't going to do something about this, they need to find a way for those solo Hunts to give you slower and minor but regular progress for the achievements.