I've found that the higher number the server, the less likely you'll get kicked. In us 21-30, there never seems to be more than 3 rows of donors in /list. In US 1-10, you really have to be the 2nd or 3rd to join, or you're gonna get kicked. I've often gotten kicked even from the #1 spot on the first few servers. It's only happened once for me on the later servers when a flood of donors randomly joined in about 30 seconds (and by the looks of the chat, there were a LOT of teams that time). Usually you're safe if you're in the first half on the last 5 or so servers.