Just to play devil's advocate, EU does get further on DTV on most maps than NA, but that's mostly only when they have a full (or near full) server and most of the peeps are organized. At the very least, their shield walls don't break up when 1 guy dies. When NA actually has enough players (about 15 or more) then we get fairly far sometimes. I've seen a group of 15 go up to the last wave of Saracen!
Now, as for OP, ninjas moved.....agreed. Extend time to join.... even more so, agreed. A few ppl in my clan ALWAYS get kicked from this (they have slower internet speeds I think) when they try and join.