Guild Wars 2

From my understanding overflows are supposed to work like this:

1. An instance in ServerA becomes full. The server checks to see if there is an existing overflow; if there is then it sends players to that overflow, if there is not then it creates a new overflow server (we will call it Overflow1)
2. Players try to join the instance in ServerA but because it is full they join Overflow1
3. An instance in ServerB becomes full. The server checks to see if there is an existing overflow; if there is then it sends players to that overflow, if there is not then it creates a new overflow server
4. Players try to join the instance in ServerB but because it is full they join Overflow1
5. Players continue to try to join ServerA and ServerB, but because they are full the end up joining Overflow1
6. Overflow1 eventually becomes “full” with players from ServerA and ServerB, so the server creates Overflow2 which are then populated by the excess of Overflow1

If this is wrong, then how does it really work because the documentation on overflow servers is vague at best.

During large events (such as the Marionette, or the Wurm) the server seems to be creating multiple Overflows at once. This can be vexing because you can end up with 2 or 3 different Overflow servers all of which are massively undermanned for such a large event.

The last Twisted Marionette event we did ended up with 2 overflow servers. The one I was in was barely half full, the other overflow had (apparently) even less than we did. Both overflow servers ended up failing due to a lack of manpower of the defenses. This makes zero sense to me, and I have seen this happen before. I have been in a party with other players and the party ended up being split up into different overflow servers, and neither of them were even close to being full.