See that you havent been to the boards much in the last 6 months or so -- cause this topic has been hammered over and over since the switch.
To make a long story short, there are lots who don't (or at least didnt) like the changes, but the overall verdict has been postive. The proof is in the pudding, as they say, and the number of players has overall skyrocketed since smaller arenas were put in.
HT's target was to have arenas of around 300 players or so. The early war arenas don't overfill, so there aren't any controls. The late war arenas' caps are set based on how full the OTHER late war arena is at the moment. Once an arena approaches being full, its partner gets more slots; and once that one fills up, the slots increase on the first one. If one is much bigger than the other, the big one's cap drops down until things even out again.
After a reset, the total number of players starts at zero -- so the partner arena will show a really low cap for a few minutes until the reset arena fills up again.
In practice, jsut go to the other LW arena and there will be no problems. You can coordinate with squaddies using the "lobby" and sending .p playername messages.